diff --git a/.beans/nuzlocke-tracker-gvom--boss-battles-level-caps-badges.md b/.beans/nuzlocke-tracker-gvom--boss-battles-level-caps-badges.md
new file mode 100644
index 0000000..843630a
--- /dev/null
+++ b/.beans/nuzlocke-tracker-gvom--boss-battles-level-caps-badges.md
@@ -0,0 +1,27 @@
+---
+# nuzlocke-tracker-gvom
+title: Boss Battles, Level Caps & Badges
+status: completed
+type: feature
+priority: normal
+created_at: 2026-02-08T10:09:33Z
+updated_at: 2026-02-08T10:15:38Z
+---
+
+Add boss battle data models, API endpoints, and UI for gym leaders, elite four, champion, etc. Includes:
+- Backend models (BossBattle, BossPokemon, BossResult)
+- Database migration
+- API endpoints for CRUD and run tracking
+- Frontend types, API client, hooks
+- Sticky level cap bar on run page
+- Boss battle cards interleaved in encounter list
+- Admin panel for managing boss battles
+
+## Checklist
+
+- [x] Phase 1: Backend models & migration
+- [x] Phase 2: Backend schemas
+- [x] Phase 3: Backend API endpoints
+- [x] Phase 4: Frontend types, API & hooks
+- [x] Phase 5: Frontend run page (level cap bar + boss cards)
+- [x] Phase 6: Frontend admin panel
\ No newline at end of file
diff --git a/backend/src/app/alembic/versions/c2d3e4f5a6b7_add_boss_battles.py b/backend/src/app/alembic/versions/c2d3e4f5a6b7_add_boss_battles.py
new file mode 100644
index 0000000..193ac7d
--- /dev/null
+++ b/backend/src/app/alembic/versions/c2d3e4f5a6b7_add_boss_battles.py
@@ -0,0 +1,61 @@
+"""add boss battles
+
+Revision ID: c2d3e4f5a6b7
+Revises: b1c2d3e4f5a6
+Create Date: 2026-02-08 12:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'c2d3e4f5a6b7'
+down_revision: Union[str, Sequence[str], None] = 'b1c2d3e4f5a6'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        'boss_battles',
+        sa.Column('id', sa.Integer(), primary_key=True),
+        sa.Column('game_id', sa.Integer(), sa.ForeignKey('games.id'), nullable=False, index=True),
+        sa.Column('name', sa.String(100), nullable=False),
+        sa.Column('boss_type', sa.String(20), nullable=False),
+        sa.Column('badge_name', sa.String(100), nullable=True),
+        sa.Column('badge_image_url', sa.String(500), nullable=True),
+        sa.Column('level_cap', sa.SmallInteger(), nullable=False),
+        sa.Column('order', sa.SmallInteger(), nullable=False),
+        sa.Column('after_route_id', sa.Integer(), sa.ForeignKey('routes.id'), nullable=True, index=True),
+        sa.Column('location', sa.String(200), nullable=False),
+        sa.Column('sprite_url', sa.String(500), nullable=True),
+    )
+
+    op.create_table(
+        'boss_pokemon',
+        sa.Column('id', sa.Integer(), primary_key=True),
+        sa.Column('boss_battle_id', sa.Integer(), sa.ForeignKey('boss_battles.id', ondelete='CASCADE'), nullable=False, index=True),
+        sa.Column('pokemon_id', sa.Integer(), sa.ForeignKey('pokemon.id'), nullable=False, index=True),
+        sa.Column('level', sa.SmallInteger(), nullable=False),
+        sa.Column('order', sa.SmallInteger(), nullable=False),
+    )
+
+    op.create_table(
+        'boss_results',
+        sa.Column('id', sa.Integer(), primary_key=True),
+        sa.Column('run_id', sa.Integer(), sa.ForeignKey('nuzlocke_runs.id', ondelete='CASCADE'), nullable=False, index=True),
+        sa.Column('boss_battle_id', sa.Integer(), sa.ForeignKey('boss_battles.id'), nullable=False, index=True),
+        sa.Column('result', sa.String(10), nullable=False),
+        sa.Column('attempts', sa.SmallInteger(), nullable=False, server_default='1'),
+        sa.Column('completed_at', sa.DateTime(timezone=True), nullable=True),
+        sa.UniqueConstraint('run_id', 'boss_battle_id', name='uq_boss_results_run_boss'),
+    )
+
+
+def downgrade() -> None:
+    op.drop_table('boss_results')
+    op.drop_table('boss_pokemon')
+    op.drop_table('boss_battles')
diff --git a/backend/src/app/api/bosses.py b/backend/src/app/api/bosses.py
new file mode 100644
index 0000000..0bcc4db
--- /dev/null
+++ b/backend/src/app/api/bosses.py
@@ -0,0 +1,240 @@
+from datetime import datetime, timezone
+
+from fastapi import APIRouter, Depends, HTTPException, Response
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy.orm import selectinload
+
+from app.core.database import get_session
+from app.models.boss_battle import BossBattle
+from app.models.boss_pokemon import BossPokemon
+from app.models.boss_result import BossResult
+from app.models.game import Game
+from app.models.nuzlocke_run import NuzlockeRun
+from app.schemas.boss import (
+    BossBattleCreate,
+    BossBattleResponse,
+    BossBattleUpdate,
+    BossPokemonInput,
+    BossResultCreate,
+    BossResultResponse,
+)
+
+router = APIRouter()
+
+
+# --- Game-scoped (admin) endpoints ---
+
+
+@router.get("/games/{game_id}/bosses", response_model=list[BossBattleResponse])
+async def list_bosses(
+    game_id: int, session: AsyncSession = Depends(get_session)
+):
+    game = await session.get(Game, game_id)
+    if game is None:
+        raise HTTPException(status_code=404, detail="Game not found")
+
+    result = await session.execute(
+        select(BossBattle)
+        .where(BossBattle.game_id == game_id)
+        .options(selectinload(BossBattle.pokemon).selectinload(BossPokemon.pokemon))
+        .order_by(BossBattle.order)
+    )
+    return result.scalars().all()
+
+
+@router.post("/games/{game_id}/bosses", response_model=BossBattleResponse, status_code=201)
+async def create_boss(
+    game_id: int,
+    data: BossBattleCreate,
+    session: AsyncSession = Depends(get_session),
+):
+    game = await session.get(Game, game_id)
+    if game is None:
+        raise HTTPException(status_code=404, detail="Game not found")
+
+    boss = BossBattle(game_id=game_id, **data.model_dump())
+    session.add(boss)
+    await session.commit()
+
+    # Re-fetch with eager loading
+    result = await session.execute(
+        select(BossBattle)
+        .where(BossBattle.id == boss.id)
+        .options(selectinload(BossBattle.pokemon).selectinload(BossPokemon.pokemon))
+    )
+    return result.scalar_one()
+
+
+@router.put("/games/{game_id}/bosses/{boss_id}", response_model=BossBattleResponse)
+async def update_boss(
+    game_id: int,
+    boss_id: int,
+    data: BossBattleUpdate,
+    session: AsyncSession = Depends(get_session),
+):
+    result = await session.execute(
+        select(BossBattle)
+        .where(BossBattle.id == boss_id, BossBattle.game_id == game_id)
+        .options(selectinload(BossBattle.pokemon).selectinload(BossPokemon.pokemon))
+    )
+    boss = result.scalar_one_or_none()
+    if boss is None:
+        raise HTTPException(status_code=404, detail="Boss battle not found")
+
+    for field, value in data.model_dump(exclude_unset=True).items():
+        setattr(boss, field, value)
+
+    await session.commit()
+    await session.refresh(boss)
+
+    # Re-fetch with eager loading
+    result = await session.execute(
+        select(BossBattle)
+        .where(BossBattle.id == boss.id)
+        .options(selectinload(BossBattle.pokemon).selectinload(BossPokemon.pokemon))
+    )
+    return result.scalar_one()
+
+
+@router.delete("/games/{game_id}/bosses/{boss_id}", status_code=204)
+async def delete_boss(
+    game_id: int,
+    boss_id: int,
+    session: AsyncSession = Depends(get_session),
+):
+    result = await session.execute(
+        select(BossBattle).where(BossBattle.id == boss_id, BossBattle.game_id == game_id)
+    )
+    boss = result.scalar_one_or_none()
+    if boss is None:
+        raise HTTPException(status_code=404, detail="Boss battle not found")
+
+    await session.delete(boss)
+    await session.commit()
+    return Response(status_code=204)
+
+
+@router.put(
+    "/games/{game_id}/bosses/{boss_id}/pokemon",
+    response_model=BossBattleResponse,
+)
+async def set_boss_team(
+    game_id: int,
+    boss_id: int,
+    team: list[BossPokemonInput],
+    session: AsyncSession = Depends(get_session),
+):
+    result = await session.execute(
+        select(BossBattle)
+        .where(BossBattle.id == boss_id, BossBattle.game_id == game_id)
+        .options(selectinload(BossBattle.pokemon))
+    )
+    boss = result.scalar_one_or_none()
+    if boss is None:
+        raise HTTPException(status_code=404, detail="Boss battle not found")
+
+    # Remove existing team
+    for p in boss.pokemon:
+        await session.delete(p)
+
+    # Add new team
+    for item in team:
+        bp = BossPokemon(
+            boss_battle_id=boss_id,
+            pokemon_id=item.pokemon_id,
+            level=item.level,
+            order=item.order,
+        )
+        session.add(bp)
+
+    await session.commit()
+
+    # Re-fetch with eager loading
+    result = await session.execute(
+        select(BossBattle)
+        .where(BossBattle.id == boss.id)
+        .options(selectinload(BossBattle.pokemon).selectinload(BossPokemon.pokemon))
+    )
+    return result.scalar_one()
+
+
+# --- Run-scoped endpoints ---
+
+
+@router.get("/runs/{run_id}/boss-results", response_model=list[BossResultResponse])
+async def list_boss_results(
+    run_id: int, session: AsyncSession = Depends(get_session)
+):
+    run = await session.get(NuzlockeRun, run_id)
+    if run is None:
+        raise HTTPException(status_code=404, detail="Run not found")
+
+    result = await session.execute(
+        select(BossResult)
+        .where(BossResult.run_id == run_id)
+        .order_by(BossResult.id)
+    )
+    return result.scalars().all()
+
+
+@router.post("/runs/{run_id}/boss-results", response_model=BossResultResponse, status_code=201)
+async def create_boss_result(
+    run_id: int,
+    data: BossResultCreate,
+    session: AsyncSession = Depends(get_session),
+):
+    run = await session.get(NuzlockeRun, run_id)
+    if run is None:
+        raise HTTPException(status_code=404, detail="Run not found")
+
+    boss = await session.get(BossBattle, data.boss_battle_id)
+    if boss is None:
+        raise HTTPException(status_code=404, detail="Boss battle not found")
+
+    # Check for existing result (upsert)
+    existing = await session.execute(
+        select(BossResult).where(
+            BossResult.run_id == run_id,
+            BossResult.boss_battle_id == data.boss_battle_id,
+        )
+    )
+    result = existing.scalar_one_or_none()
+
+    if result:
+        result.result = data.result
+        result.attempts = data.attempts
+        result.completed_at = datetime.now(timezone.utc) if data.result == "won" else None
+    else:
+        result = BossResult(
+            run_id=run_id,
+            boss_battle_id=data.boss_battle_id,
+            result=data.result,
+            attempts=data.attempts,
+            completed_at=datetime.now(timezone.utc) if data.result == "won" else None,
+        )
+        session.add(result)
+
+    await session.commit()
+    await session.refresh(result)
+    return result
+
+
+@router.delete("/runs/{run_id}/boss-results/{result_id}", status_code=204)
+async def delete_boss_result(
+    run_id: int,
+    result_id: int,
+    session: AsyncSession = Depends(get_session),
+):
+    result = await session.execute(
+        select(BossResult).where(
+            BossResult.id == result_id, BossResult.run_id == run_id
+        )
+    )
+    boss_result = result.scalar_one_or_none()
+    if boss_result is None:
+        raise HTTPException(status_code=404, detail="Boss result not found")
+
+    await session.delete(boss_result)
+    await session.commit()
+    return Response(status_code=204)
diff --git a/backend/src/app/api/routes.py b/backend/src/app/api/routes.py
index da8b9ee..1678e94 100644
--- a/backend/src/app/api/routes.py
+++ b/backend/src/app/api/routes.py
@@ -1,6 +1,6 @@
 from fastapi import APIRouter
 
-from app.api import encounters, evolutions, export, games, health, pokemon, runs, stats
+from app.api import bosses, encounters, evolutions, export, games, health, pokemon, runs, stats
 
 api_router = APIRouter()
 api_router.include_router(health.router)
@@ -10,4 +10,5 @@ api_router.include_router(evolutions.router, tags=["evolutions"])
 api_router.include_router(runs.router, prefix="/runs", tags=["runs"])
 api_router.include_router(encounters.router, tags=["encounters"])
 api_router.include_router(stats.router, prefix="/stats", tags=["stats"])
+api_router.include_router(bosses.router, tags=["bosses"])
 api_router.include_router(export.router, prefix="/export", tags=["export"])
diff --git a/backend/src/app/models/__init__.py b/backend/src/app/models/__init__.py
index 73c49dc..a762748 100644
--- a/backend/src/app/models/__init__.py
+++ b/backend/src/app/models/__init__.py
@@ -1,3 +1,6 @@
+from app.models.boss_battle import BossBattle
+from app.models.boss_pokemon import BossPokemon
+from app.models.boss_result import BossResult
 from app.models.encounter import Encounter
 from app.models.evolution import Evolution
 from app.models.game import Game
@@ -7,6 +10,9 @@ from app.models.route import Route
 from app.models.route_encounter import RouteEncounter
 
 __all__ = [
+    "BossBattle",
+    "BossPokemon",
+    "BossResult",
     "Encounter",
     "Evolution",
     "Game",
diff --git a/backend/src/app/models/boss_battle.py b/backend/src/app/models/boss_battle.py
new file mode 100644
index 0000000..525e9f3
--- /dev/null
+++ b/backend/src/app/models/boss_battle.py
@@ -0,0 +1,31 @@
+from sqlalchemy import ForeignKey, SmallInteger, String
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.core.database import Base
+
+
+class BossBattle(Base):
+    __tablename__ = "boss_battles"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    game_id: Mapped[int] = mapped_column(ForeignKey("games.id"), index=True)
+    name: Mapped[str] = mapped_column(String(100))
+    boss_type: Mapped[str] = mapped_column(String(20))  # gym_leader, elite_four, champion, rival, evil_team, other
+    badge_name: Mapped[str | None] = mapped_column(String(100))
+    badge_image_url: Mapped[str | None] = mapped_column(String(500))
+    level_cap: Mapped[int] = mapped_column(SmallInteger)
+    order: Mapped[int] = mapped_column(SmallInteger)
+    after_route_id: Mapped[int | None] = mapped_column(
+        ForeignKey("routes.id"), index=True, default=None
+    )
+    location: Mapped[str] = mapped_column(String(200))
+    sprite_url: Mapped[str | None] = mapped_column(String(500))
+
+    game: Mapped["Game"] = relationship(back_populates="boss_battles")
+    after_route: Mapped["Route | None"] = relationship()
+    pokemon: Mapped[list["BossPokemon"]] = relationship(
+        back_populates="boss_battle", cascade="all, delete-orphan"
+    )
+
+    def __repr__(self) -> str:
+        return f"<BossBattle(id={self.id}, name='{self.name}', type='{self.boss_type}')>"
diff --git a/backend/src/app/models/boss_pokemon.py b/backend/src/app/models/boss_pokemon.py
new file mode 100644
index 0000000..39014f5
--- /dev/null
+++ b/backend/src/app/models/boss_pokemon.py
@@ -0,0 +1,22 @@
+from sqlalchemy import ForeignKey, SmallInteger
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.core.database import Base
+
+
+class BossPokemon(Base):
+    __tablename__ = "boss_pokemon"
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    boss_battle_id: Mapped[int] = mapped_column(
+        ForeignKey("boss_battles.id", ondelete="CASCADE"), index=True
+    )
+    pokemon_id: Mapped[int] = mapped_column(ForeignKey("pokemon.id"), index=True)
+    level: Mapped[int] = mapped_column(SmallInteger)
+    order: Mapped[int] = mapped_column(SmallInteger)
+
+    boss_battle: Mapped["BossBattle"] = relationship(back_populates="pokemon")
+    pokemon: Mapped["Pokemon"] = relationship()
+
+    def __repr__(self) -> str:
+        return f"<BossPokemon(id={self.id}, boss_battle_id={self.boss_battle_id}, pokemon_id={self.pokemon_id})>"
diff --git a/backend/src/app/models/boss_result.py b/backend/src/app/models/boss_result.py
new file mode 100644
index 0000000..4cd4ca7
--- /dev/null
+++ b/backend/src/app/models/boss_result.py
@@ -0,0 +1,30 @@
+from datetime import datetime
+
+from sqlalchemy import DateTime, ForeignKey, SmallInteger, String, UniqueConstraint
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.core.database import Base
+
+
+class BossResult(Base):
+    __tablename__ = "boss_results"
+    __table_args__ = (
+        UniqueConstraint("run_id", "boss_battle_id", name="uq_boss_results_run_boss"),
+    )
+
+    id: Mapped[int] = mapped_column(primary_key=True)
+    run_id: Mapped[int] = mapped_column(
+        ForeignKey("nuzlocke_runs.id", ondelete="CASCADE"), index=True
+    )
+    boss_battle_id: Mapped[int] = mapped_column(
+        ForeignKey("boss_battles.id"), index=True
+    )
+    result: Mapped[str] = mapped_column(String(10))  # won, lost
+    attempts: Mapped[int] = mapped_column(SmallInteger, default=1)
+    completed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+
+    run: Mapped["NuzlockeRun"] = relationship(back_populates="boss_results")
+    boss_battle: Mapped["BossBattle"] = relationship()
+
+    def __repr__(self) -> str:
+        return f"<BossResult(id={self.id}, run_id={self.run_id}, boss_battle_id={self.boss_battle_id}, result='{self.result}')>"
diff --git a/backend/src/app/models/game.py b/backend/src/app/models/game.py
index 5fca8e3..84b36e8 100644
--- a/backend/src/app/models/game.py
+++ b/backend/src/app/models/game.py
@@ -18,6 +18,7 @@ class Game(Base):
 
     routes: Mapped[list["Route"]] = relationship(back_populates="game")
     runs: Mapped[list["NuzlockeRun"]] = relationship(back_populates="game")
+    boss_battles: Mapped[list["BossBattle"]] = relationship(back_populates="game")
 
     def __repr__(self) -> str:
         return f"<Game(id={self.id}, name='{self.name}')>"
diff --git a/backend/src/app/models/nuzlocke_run.py b/backend/src/app/models/nuzlocke_run.py
index a2dfd18..69d4f15 100644
--- a/backend/src/app/models/nuzlocke_run.py
+++ b/backend/src/app/models/nuzlocke_run.py
@@ -22,6 +22,7 @@ class NuzlockeRun(Base):
 
     game: Mapped["Game"] = relationship(back_populates="runs")
     encounters: Mapped[list["Encounter"]] = relationship(back_populates="run")
+    boss_results: Mapped[list["BossResult"]] = relationship(back_populates="run")
 
     def __repr__(self) -> str:
         return f"<NuzlockeRun(id={self.id}, name='{self.name}', status='{self.status}')>"
diff --git a/backend/src/app/schemas/__init__.py b/backend/src/app/schemas/__init__.py
index 2aecc76..6547db7 100644
--- a/backend/src/app/schemas/__init__.py
+++ b/backend/src/app/schemas/__init__.py
@@ -1,3 +1,13 @@
+from app.schemas.boss import (
+    BossBattleCreate,
+    BossBattleResponse,
+    BossBattleUpdate,
+    BossPokemonInput,
+    BossPokemonResponse,
+    BossResultCreate,
+    BossResultResponse,
+    BossResultUpdate,
+)
 from app.schemas.encounter import (
     EncounterCreate,
     EncounterDetailResponse,
@@ -29,6 +39,14 @@ from app.schemas.pokemon import (
 from app.schemas.run import RunCreate, RunDetailResponse, RunResponse, RunUpdate
 
 __all__ = [
+    "BossBattleCreate",
+    "BossBattleResponse",
+    "BossBattleUpdate",
+    "BossPokemonInput",
+    "BossPokemonResponse",
+    "BossResultCreate",
+    "BossResultResponse",
+    "BossResultUpdate",
     "BulkImportItem",
     "BulkImportResult",
     "EncounterCreate",
diff --git a/backend/src/app/schemas/boss.py b/backend/src/app/schemas/boss.py
new file mode 100644
index 0000000..42c3a54
--- /dev/null
+++ b/backend/src/app/schemas/boss.py
@@ -0,0 +1,80 @@
+from datetime import datetime
+
+from app.schemas.base import CamelModel
+from app.schemas.pokemon import PokemonResponse
+
+
+class BossPokemonResponse(CamelModel):
+    id: int
+    pokemon_id: int
+    level: int
+    order: int
+    pokemon: PokemonResponse
+
+
+class BossBattleResponse(CamelModel):
+    id: int
+    game_id: int
+    name: str
+    boss_type: str
+    badge_name: str | None
+    badge_image_url: str | None
+    level_cap: int
+    order: int
+    after_route_id: int | None
+    location: str
+    sprite_url: str | None
+    pokemon: list[BossPokemonResponse] = []
+
+
+class BossResultResponse(CamelModel):
+    id: int
+    run_id: int
+    boss_battle_id: int
+    result: str
+    attempts: int
+    completed_at: datetime | None
+
+
+# --- Input schemas ---
+
+
+class BossBattleCreate(CamelModel):
+    name: str
+    boss_type: str
+    badge_name: str | None = None
+    badge_image_url: str | None = None
+    level_cap: int
+    order: int
+    after_route_id: int | None = None
+    location: str
+    sprite_url: str | None = None
+
+
+class BossBattleUpdate(CamelModel):
+    name: str | None = None
+    boss_type: str | None = None
+    badge_name: str | None = None
+    badge_image_url: str | None = None
+    level_cap: int | None = None
+    order: int | None = None
+    after_route_id: int | None = None
+    location: str | None = None
+    sprite_url: str | None = None
+
+
+class BossPokemonInput(CamelModel):
+    pokemon_id: int
+    level: int
+    order: int
+
+
+class BossResultCreate(CamelModel):
+    boss_battle_id: int
+    result: str
+    attempts: int = 1
+
+
+class BossResultUpdate(CamelModel):
+    result: str | None = None
+    attempts: int | None = None
diff --git a/frontend/src/api/admin.ts b/frontend/src/api/admin.ts
index 739ac16..0ed7570 100644
--- a/frontend/src/api/admin.ts
+++ b/frontend/src/api/admin.ts
@@ -4,6 +4,7 @@ import type {
   Route,
   Pokemon,
   RouteEncounterDetail,
+  BossBattle,
   CreateGameInput,
   UpdateGameInput,
   CreateRouteInput,
@@ -19,6 +20,9 @@ import type {
   PaginatedEvolutions,
   CreateEvolutionInput,
   UpdateEvolutionInput,
+  CreateBossBattleInput,
+  UpdateBossBattleInput,
+  BossPokemonInput,
 } from '../types'
 
 // Games
@@ -105,3 +109,16 @@ export const updateRouteEncounter = (routeId: number, encounterId: number, data:
 
 export const removeRouteEncounter = (routeId: number, encounterId: number) =>
   api.del(`/routes/${routeId}/pokemon/${encounterId}`)
+
+// Boss Battles
+export const createBossBattle = (gameId: number, data: CreateBossBattleInput) =>
+  api.post<BossBattle>(`/games/${gameId}/bosses`, data)
+
+export const updateBossBattle = (gameId: number, bossId: number, data: UpdateBossBattleInput) =>
+  api.put<BossBattle>(`/games/${gameId}/bosses/${bossId}`, data)
+
+export const deleteBossBattle = (gameId: number, bossId: number) =>
+  api.del(`/games/${gameId}/bosses/${bossId}`)
+
+export const setBossTeam = (gameId: number, bossId: number, team: BossPokemonInput[]) =>
+  api.put<BossBattle>(`/games/${gameId}/bosses/${bossId}/pokemon`, team)
diff --git a/frontend/src/api/bosses.ts b/frontend/src/api/bosses.ts
new file mode 100644
index 0000000..1f4f971
--- /dev/null
+++ b/frontend/src/api/bosses.ts
@@ -0,0 +1,18 @@
+import { api } from './client'
+import type { BossBattle, BossResult, CreateBossResultInput } from '../types/game'
+
+export function getGameBosses(gameId: number): Promise<BossBattle[]> {
+  return api.get(`/games/${gameId}/bosses`)
+}
+
+export function getBossResults(runId: number): Promise<BossResult[]> {
+  return api.get(`/runs/${runId}/boss-results`)
+}
+
+export function createBossResult(runId: number, data: CreateBossResultInput): Promise<BossResult> {
+  return api.post(`/runs/${runId}/boss-results`, data)
+}
+
+export function deleteBossResult(runId: number, resultId: number): Promise<void> {
+  return api.del(`/runs/${runId}/boss-results/${resultId}`)
+}
diff --git a/frontend/src/components/BossDefeatModal.tsx b/frontend/src/components/BossDefeatModal.tsx
new file mode 100644
index 0000000..e3c2089
--- /dev/null
+++ b/frontend/src/components/BossDefeatModal.tsx
@@ -0,0 +1,120 @@
+import { type FormEvent, useState } from 'react'
+import type { BossBattle, CreateBossResultInput } from '../types/game'
+
+interface BossDefeatModalProps {
+  boss: BossBattle
+  onSubmit: (data: CreateBossResultInput) => void
+  onClose: () => void
+  isPending?: boolean
+}
+
+export function BossDefeatModal({ boss, onSubmit, onClose, isPending }: BossDefeatModalProps) {
+  const [result, setResult] = useState<'won' | 'lost'>('won')
+  const [attempts, setAttempts] = useState('1')
+
+  const handleSubmit = (e: FormEvent) => {
+    e.preventDefault()
+    onSubmit({
+      bossBattleId: boss.id,
+      result,
+      attempts: Number(attempts) || 1,
+    })
+  }
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center">
+      <div className="fixed inset-0 bg-black/50" onClick={onClose} />
+      <div className="relative bg-white dark:bg-gray-800 rounded-lg shadow-xl max-w-md w-full mx-4">
+        <div className="px-6 py-4 border-b border-gray-200 dark:border-gray-700">
+          <h2 className="text-lg font-semibold">Battle: {boss.name}</h2>
+          <p className="text-sm text-gray-500 dark:text-gray-400">{boss.location}</p>
+        </div>
+
+        {/* Boss team preview */}
+        {boss.pokemon.length > 0 && (
+          <div className="px-6 py-3 border-b border-gray-200 dark:border-gray-700">
+            <div className="flex flex-wrap gap-3">
+              {boss.pokemon
+                .sort((a, b) => a.order - b.order)
+                .map((bp) => (
+                  <div key={bp.id} className="flex flex-col items-center">
+                    {bp.pokemon.spriteUrl ? (
+                      <img src={bp.pokemon.spriteUrl} alt={bp.pokemon.name} className="w-10 h-10" />
+                    ) : (
+                      <div className="w-10 h-10 bg-gray-200 dark:bg-gray-700 rounded-full" />
+                    )}
+                    <span className="text-xs text-gray-500 dark:text-gray-400 capitalize">
+                      {bp.pokemon.name}
+                    </span>
+                    <span className="text-xs font-medium text-gray-700 dark:text-gray-300">
+                      Lv.{bp.level}
+                    </span>
+                  </div>
+                ))}
+            </div>
+          </div>
+        )}
+
+        <form onSubmit={handleSubmit}>
+          <div className="px-6 py-4 space-y-4">
+            <div>
+              <label className="block text-sm font-medium mb-2">Result</label>
+              <div className="flex gap-2">
+                <button
+                  type="button"
+                  onClick={() => setResult('won')}
+                  className={`flex-1 px-3 py-2 text-sm font-medium rounded-md border transition-colors ${
+                    result === 'won'
+                      ? 'bg-green-600 text-white border-green-600'
+                      : 'border-gray-300 dark:border-gray-600 hover:bg-gray-50 dark:hover:bg-gray-700'
+                  }`}
+                >
+                  Won
+                </button>
+                <button
+                  type="button"
+                  onClick={() => setResult('lost')}
+                  className={`flex-1 px-3 py-2 text-sm font-medium rounded-md border transition-colors ${
+                    result === 'lost'
+                      ? 'bg-red-600 text-white border-red-600'
+                      : 'border-gray-300 dark:border-gray-600 hover:bg-gray-50 dark:hover:bg-gray-700'
+                  }`}
+                >
+                  Lost
+                </button>
+              </div>
+            </div>
+
+            <div>
+              <label className="block text-sm font-medium mb-1">Attempts</label>
+              <input
+                type="number"
+                min={1}
+                value={attempts}
+                onChange={(e) => setAttempts(e.target.value)}
+                className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+              />
+            </div>
+          </div>
+
+          <div className="px-6 py-4 border-t border-gray-200 dark:border-gray-700 flex justify-end gap-3">
+            <button
+              type="button"
+              onClick={onClose}
+              className="px-4 py-2 text-sm font-medium rounded-md border border-gray-300 dark:border-gray-600 hover:bg-gray-50 dark:hover:bg-gray-700"
+            >
+              Cancel
+            </button>
+            <button
+              type="submit"
+              disabled={isPending}
+              className="px-4 py-2 text-sm font-medium rounded-md bg-blue-600 text-white hover:bg-blue-700 disabled:opacity-50"
+            >
+              {isPending ? 'Saving...' : 'Save Result'}
+            </button>
+          </div>
+        </form>
+      </div>
+    </div>
+  )
+}
diff --git a/frontend/src/components/admin/BossBattleFormModal.tsx b/frontend/src/components/admin/BossBattleFormModal.tsx
new file mode 100644
index 0000000..b297a88
--- /dev/null
+++ b/frontend/src/components/admin/BossBattleFormModal.tsx
@@ -0,0 +1,183 @@
+import { type FormEvent, useState } from 'react'
+import { FormModal } from './FormModal'
+import type { BossBattle, Route } from '../../types/game'
+import type { CreateBossBattleInput, UpdateBossBattleInput } from '../../types/admin'
+
+interface BossBattleFormModalProps {
+  boss?: BossBattle
+  routes: Route[]
+  nextOrder: number
+  onSubmit: (data: CreateBossBattleInput | UpdateBossBattleInput) => void
+  onClose: () => void
+  isSubmitting?: boolean
+}
+
+const BOSS_TYPES = [
+  { value: 'gym_leader', label: 'Gym Leader' },
+  { value: 'elite_four', label: 'Elite Four' },
+  { value: 'champion', label: 'Champion' },
+  { value: 'rival', label: 'Rival' },
+  { value: 'evil_team', label: 'Evil Team' },
+  { value: 'other', label: 'Other' },
+]
+
+export function BossBattleFormModal({
+  boss,
+  routes,
+  nextOrder,
+  onSubmit,
+  onClose,
+  isSubmitting,
+}: BossBattleFormModalProps) {
+  const [name, setName] = useState(boss?.name ?? '')
+  const [bossType, setBossType] = useState(boss?.bossType ?? 'gym_leader')
+  const [badgeName, setBadgeName] = useState(boss?.badgeName ?? '')
+  const [badgeImageUrl, setBadgeImageUrl] = useState(boss?.badgeImageUrl ?? '')
+  const [levelCap, setLevelCap] = useState(String(boss?.levelCap ?? ''))
+  const [order, setOrder] = useState(String(boss?.order ?? nextOrder))
+  const [afterRouteId, setAfterRouteId] = useState(String(boss?.afterRouteId ?? ''))
+  const [location, setLocation] = useState(boss?.location ?? '')
+  const [spriteUrl, setSpriteUrl] = useState(boss?.spriteUrl ?? '')
+
+  const handleSubmit = (e: FormEvent) => {
+    e.preventDefault()
+    onSubmit({
+      name,
+      bossType,
+      badgeName: badgeName || null,
+      badgeImageUrl: badgeImageUrl || null,
+      levelCap: Number(levelCap),
+      order: Number(order),
+      afterRouteId: afterRouteId ? Number(afterRouteId) : null,
+      location,
+      spriteUrl: spriteUrl || null,
+    })
+  }
+
+  // Sort routes by order for the dropdown
+  const sortedRoutes = [...routes].sort((a, b) => a.order - b.order)
+
+  return (
+    <FormModal
+      title={boss ? 'Edit Boss Battle' : 'Add Boss Battle'}
+      onClose={onClose}
+      onSubmit={handleSubmit}
+      isSubmitting={isSubmitting}
+    >
+      <div className="grid grid-cols-2 gap-4">
+        <div>
+          <label className="block text-sm font-medium mb-1">Name</label>
+          <input
+            type="text"
+            required
+            value={name}
+            onChange={(e) => setName(e.target.value)}
+            placeholder="e.g. Brock"
+            className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+          />
+        </div>
+        <div>
+          <label className="block text-sm font-medium mb-1">Type</label>
+          <select
+            value={bossType}
+            onChange={(e) => setBossType(e.target.value)}
+            className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+          >
+            {BOSS_TYPES.map((t) => (
+              <option key={t.value} value={t.value}>
+                {t.label}
+              </option>
+            ))}
+          </select>
+        </div>
+      </div>
+
+      <div>
+        <label className="block text-sm font-medium mb-1">Location</label>
+        <input
+          type="text"
+          required
+          value={location}
+          onChange={(e) => setLocation(e.target.value)}
+          placeholder="e.g. Pewter City Gym"
+          className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+        />
+      </div>
+
+      <div className="grid grid-cols-2 gap-4">
+        <div>
+          <label className="block text-sm font-medium mb-1">Level Cap</label>
+          <input
+            type="number"
+            required
+            min={1}
+            value={levelCap}
+            onChange={(e) => setLevelCap(e.target.value)}
+            className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+          />
+        </div>
+        <div>
+          <label className="block text-sm font-medium mb-1">Order</label>
+          <input
+            type="number"
+            required
+            min={1}
+            value={order}
+            onChange={(e) => setOrder(e.target.value)}
+            className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+          />
+        </div>
+      </div>
+
+      <div>
+        <label className="block text-sm font-medium mb-1">Position After Route</label>
+        <select
+          value={afterRouteId}
+          onChange={(e) => setAfterRouteId(e.target.value)}
+          className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+        >
+          <option value="">None</option>
+          {sortedRoutes.map((r) => (
+            <option key={r.id} value={r.id}>
+              {r.order}. {r.name}
+            </option>
+          ))}
+        </select>
+      </div>
+
+      <div className="grid grid-cols-2 gap-4">
+        <div>
+          <label className="block text-sm font-medium mb-1">Badge Name</label>
+          <input
+            type="text"
+            value={badgeName}
+            onChange={(e) => setBadgeName(e.target.value)}
+            placeholder="Optional"
+            className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+          />
+        </div>
+        <div>
+          <label className="block text-sm font-medium mb-1">Badge Image URL</label>
+          <input
+            type="text"
+            value={badgeImageUrl}
+            onChange={(e) => setBadgeImageUrl(e.target.value)}
+            placeholder="Optional"
+            className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+          />
+        </div>
+      </div>
+
+      <div>
+        <label className="block text-sm font-medium mb-1">Sprite URL</label>
+        <input
+          type="text"
+          value={spriteUrl}
+          onChange={(e) => setSpriteUrl(e.target.value)}
+          placeholder="Optional"
+          className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+        />
+      </div>
+    </FormModal>
+  )
+}
diff --git a/frontend/src/components/admin/BossTeamEditor.tsx b/frontend/src/components/admin/BossTeamEditor.tsx
new file mode 100644
index 0000000..f9a347e
--- /dev/null
+++ b/frontend/src/components/admin/BossTeamEditor.tsx
@@ -0,0 +1,129 @@
+import { type FormEvent, useState } from 'react'
+import { PokemonSelector } from './PokemonSelector'
+import type { BossBattle } from '../../types/game'
+import type { BossPokemonInput } from '../../types/admin'
+
+interface BossTeamEditorProps {
+  boss: BossBattle
+  onSave: (team: BossPokemonInput[]) => void
+  onClose: () => void
+  isSaving?: boolean
+}
+
+export function BossTeamEditor({ boss, onSave, onClose, isSaving }: BossTeamEditorProps) {
+  const [team, setTeam] = useState<Array<{ pokemonId: number | null; pokemonName: string; level: string; order: number }>>(
+    boss.pokemon.length > 0
+      ? boss.pokemon
+          .sort((a, b) => a.order - b.order)
+          .map((bp) => ({
+            pokemonId: bp.pokemonId,
+            pokemonName: bp.pokemon.name,
+            level: String(bp.level),
+            order: bp.order,
+          }))
+      : [{ pokemonId: null, pokemonName: '', level: '', order: 1 }],
+  )
+
+  const addSlot = () => {
+    setTeam((prev) => [
+      ...prev,
+      { pokemonId: null, pokemonName: '', level: '', order: prev.length + 1 },
+    ])
+  }
+
+  const removeSlot = (index: number) => {
+    setTeam((prev) => prev.filter((_, i) => i !== index).map((item, i) => ({ ...item, order: i + 1 })))
+  }
+
+  const updateSlot = (index: number, field: string, value: number | string | null) => {
+    setTeam((prev) =>
+      prev.map((item, i) => (i === index ? { ...item, [field]: value } : item)),
+    )
+  }
+
+  const handleSubmit = (e: FormEvent) => {
+    e.preventDefault()
+    const validTeam: BossPokemonInput[] = team
+      .filter((t) => t.pokemonId != null && t.level)
+      .map((t, i) => ({
+        pokemonId: t.pokemonId!,
+        level: Number(t.level),
+        order: i + 1,
+      }))
+    onSave(validTeam)
+  }
+
+  return (
+    <div className="fixed inset-0 z-50 flex items-center justify-center">
+      <div className="fixed inset-0 bg-black/50" onClick={onClose} />
+      <div className="relative bg-white dark:bg-gray-800 rounded-lg shadow-xl max-w-lg w-full mx-4 max-h-[90vh] overflow-y-auto">
+        <div className="px-6 py-4 border-b border-gray-200 dark:border-gray-700">
+          <h2 className="text-lg font-semibold">{boss.name}'s Team</h2>
+        </div>
+
+        <form onSubmit={handleSubmit}>
+          <div className="px-6 py-4 space-y-3">
+            {team.map((slot, index) => (
+              <div key={index} className="flex items-end gap-2">
+                <div className="flex-1">
+                  <PokemonSelector
+                    label={`Pokemon ${index + 1}`}
+                    selectedId={slot.pokemonId}
+                    initialName={slot.pokemonName}
+                    onChange={(id) => updateSlot(index, 'pokemonId', id)}
+                  />
+                </div>
+                <div className="w-20">
+                  <label className="block text-sm font-medium mb-1">Level</label>
+                  <input
+                    type="number"
+                    min={1}
+                    max={100}
+                    value={slot.level}
+                    onChange={(e) => updateSlot(index, 'level', e.target.value)}
+                    className="w-full px-3 py-2 border rounded-md dark:bg-gray-700 dark:border-gray-600"
+                  />
+                </div>
+                <button
+                  type="button"
+                  onClick={() => removeSlot(index)}
+                  className="px-2 py-2 text-red-500 hover:text-red-700 text-sm"
+                  title="Remove"
+                >
+                  &#10005;
+                </button>
+              </div>
+            ))}
+
+            {team.length < 6 && (
+              <button
+                type="button"
+                onClick={addSlot}
+                className="w-full py-2 text-sm text-blue-600 dark:text-blue-400 border border-dashed border-gray-300 dark:border-gray-600 rounded-md hover:bg-gray-50 dark:hover:bg-gray-700"
+              >
+                + Add Pokemon
+              </button>
+            )}
+          </div>
+
+          <div className="px-6 py-4 border-t border-gray-200 dark:border-gray-700 flex justify-end gap-3">
+            <button
+              type="button"
+              onClick={onClose}
+              className="px-4 py-2 text-sm font-medium rounded-md border border-gray-300 dark:border-gray-600 hover:bg-gray-50 dark:hover:bg-gray-700"
+            >
+              Cancel
+            </button>
+            <button
+              type="submit"
+              disabled={isSaving}
+              className="px-4 py-2 text-sm font-medium rounded-md bg-blue-600 text-white hover:bg-blue-700 disabled:opacity-50"
+            >
+              {isSaving ? 'Saving...' : 'Save Team'}
+            </button>
+          </div>
+        </form>
+      </div>
+    </div>
+  )
+}
diff --git a/frontend/src/hooks/useAdmin.ts b/frontend/src/hooks/useAdmin.ts
index 66a5038..70bf448 100644
--- a/frontend/src/hooks/useAdmin.ts
+++ b/frontend/src/hooks/useAdmin.ts
@@ -13,6 +13,9 @@ import type {
   UpdateRouteEncounterInput,
   CreateEvolutionInput,
   UpdateEvolutionInput,
+  CreateBossBattleInput,
+  UpdateBossBattleInput,
+  BossPokemonInput,
 } from '../types'
 
 // --- Queries ---
@@ -256,3 +259,54 @@ export function useRemoveRouteEncounter(routeId: number) {
     onError: (err) => toast.error(`Failed to remove encounter: ${err.message}`),
   })
 }
+
+// --- Boss Battle Mutations ---
+
+export function useCreateBossBattle(gameId: number) {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: (data: CreateBossBattleInput) => adminApi.createBossBattle(gameId, data),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['games', gameId, 'bosses'] })
+      toast.success('Boss battle created')
+    },
+    onError: (err) => toast.error(`Failed to create boss battle: ${err.message}`),
+  })
+}
+
+export function useUpdateBossBattle(gameId: number) {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: ({ bossId, data }: { bossId: number; data: UpdateBossBattleInput }) =>
+      adminApi.updateBossBattle(gameId, bossId, data),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['games', gameId, 'bosses'] })
+      toast.success('Boss battle updated')
+    },
+    onError: (err) => toast.error(`Failed to update boss battle: ${err.message}`),
+  })
+}
+
+export function useDeleteBossBattle(gameId: number) {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: (bossId: number) => adminApi.deleteBossBattle(gameId, bossId),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['games', gameId, 'bosses'] })
+      toast.success('Boss battle deleted')
+    },
+    onError: (err) => toast.error(`Failed to delete boss battle: ${err.message}`),
+  })
+}
+
+export function useSetBossTeam(gameId: number, bossId: number) {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: (team: BossPokemonInput[]) => adminApi.setBossTeam(gameId, bossId, team),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['games', gameId, 'bosses'] })
+      toast.success('Boss team updated')
+    },
+    onError: (err) => toast.error(`Failed to update boss team: ${err.message}`),
+  })
+}
diff --git a/frontend/src/hooks/useBosses.ts b/frontend/src/hooks/useBosses.ts
new file mode 100644
index 0000000..17f52c9
--- /dev/null
+++ b/frontend/src/hooks/useBosses.ts
@@ -0,0 +1,43 @@
+import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
+import { toast } from 'sonner'
+import { getGameBosses, getBossResults, createBossResult, deleteBossResult } from '../api/bosses'
+import type { CreateBossResultInput } from '../types/game'
+
+export function useGameBosses(gameId: number | null) {
+  return useQuery({
+    queryKey: ['games', gameId, 'bosses'],
+    queryFn: () => getGameBosses(gameId!),
+    enabled: gameId != null,
+  })
+}
+
+export function useBossResults(runId: number) {
+  return useQuery({
+    queryKey: ['runs', runId, 'boss-results'],
+    queryFn: () => getBossResults(runId),
+  })
+}
+
+export function useCreateBossResult(runId: number) {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: (data: CreateBossResultInput) => createBossResult(runId, data),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['runs', runId, 'boss-results'] })
+      toast.success('Boss result recorded')
+    },
+    onError: (err) => toast.error(`Failed to record result: ${err.message}`),
+  })
+}
+
+export function useDeleteBossResult(runId: number) {
+  const qc = useQueryClient()
+  return useMutation({
+    mutationFn: (resultId: number) => deleteBossResult(runId, resultId),
+    onSuccess: () => {
+      qc.invalidateQueries({ queryKey: ['runs', runId, 'boss-results'] })
+      toast.success('Boss result removed')
+    },
+    onError: (err) => toast.error(`Failed to remove result: ${err.message}`),
+  })
+}
diff --git a/frontend/src/pages/RunEncounters.tsx b/frontend/src/pages/RunEncounters.tsx
index 5a44402..f1456f8 100644
--- a/frontend/src/pages/RunEncounters.tsx
+++ b/frontend/src/pages/RunEncounters.tsx
@@ -4,6 +4,7 @@ import { useRun, useUpdateRun } from '../hooks/useRuns'
 import { useGameRoutes } from '../hooks/useGames'
 import { useCreateEncounter, useUpdateEncounter } from '../hooks/useEncounters'
 import { usePokemonFamilies } from '../hooks/usePokemon'
+import { useGameBosses, useBossResults, useCreateBossResult } from '../hooks/useBosses'
 import {
   EncounterModal,
   EncounterMethodBadge,
@@ -15,6 +16,7 @@ import {
   ShinyBox,
   ShinyEncounterModal,
 } from '../components'
+import { BossDefeatModal } from '../components/BossDefeatModal'
 import type {
   Route,
   RouteWithChildren,
@@ -22,6 +24,7 @@ import type {
   EncounterDetail,
   EncounterStatus,
   CreateEncounterInput,
+  BossBattle,
 } from '../types'
 
 const statusStyles: Record<RunStatus, string> = {
@@ -322,8 +325,12 @@ export function RunEncounters() {
   const updateEncounter = useUpdateEncounter(runIdNum)
   const updateRun = useUpdateRun(runIdNum)
   const { data: familiesData } = usePokemonFamilies()
+  const { data: bosses } = useGameBosses(run?.gameId ?? null)
+  const { data: bossResults } = useBossResults(runIdNum)
+  const createBossResult = useCreateBossResult(runIdNum)
 
   const [selectedRoute, setSelectedRoute] = useState<Route | null>(null)
+  const [selectedBoss, setSelectedBoss] = useState<BossBattle | null>(null)
   const [editingEncounter, setEditingEncounter] =
     useState<EncounterDetail | null>(null)
   const [selectedTeamEncounter, setSelectedTeamEncounter] =
@@ -420,6 +427,50 @@ export function RunEncounters() {
     return duped.size > 0 ? duped : undefined
   }, [run, normalEncounters, familiesData])
 
+  // Boss battle data
+  const defeatedBossIds = useMemo(() => {
+    const set = new Set<number>()
+    if (bossResults) {
+      for (const r of bossResults) {
+        if (r.result === 'won') set.add(r.bossBattleId)
+      }
+    }
+    return set
+  }, [bossResults])
+
+  const sortedBosses = useMemo(() => {
+    if (!bosses) return []
+    return [...bosses].sort((a, b) => a.order - b.order)
+  }, [bosses])
+
+  const nextBoss = useMemo(() => {
+    return sortedBosses.find((b) => !defeatedBossIds.has(b.id)) ?? null
+  }, [sortedBosses, defeatedBossIds])
+
+  const currentLevelCap = useMemo(() => {
+    if (!nextBoss) {
+      // All defeated — no cap (or use last boss's level)
+      return sortedBosses.length > 0
+        ? sortedBosses[sortedBosses.length - 1].levelCap
+        : null
+    }
+    return nextBoss.levelCap
+  }, [nextBoss, sortedBosses])
+
+  // Map afterRouteId → BossBattle[] for interleaving
+  const bossesAfterRoute = useMemo(() => {
+    const map = new Map<number, BossBattle[]>()
+    if (!bosses) return map
+    for (const boss of bosses) {
+      if (boss.afterRouteId != null) {
+        const list = map.get(boss.afterRouteId) ?? []
+        list.push(boss)
+        map.set(boss.afterRouteId, list)
+      }
+    }
+    return map
+  }, [bosses])
+
   // Auto-expand the first unvisited group on initial load
   useEffect(() => {
     if (organizedRoutes.length === 0 || expandedGroups.size > 0) return
@@ -677,6 +728,65 @@ export function RunEncounters() {
         />
       </div>
 
+      {/* Level Cap Bar */}
+      {run.rules?.levelCaps && sortedBosses.length > 0 && (
+        <div className="sticky top-0 z-10 bg-white dark:bg-gray-900 border border-gray-200 dark:border-gray-700 rounded-lg px-4 py-3 mb-6 shadow-sm">
+          <div className="flex items-center justify-between mb-2">
+            <div className="flex items-center gap-3">
+              <span className="text-sm font-semibold text-gray-900 dark:text-gray-100">
+                Level Cap: {currentLevelCap ?? '—'}
+              </span>
+              {nextBoss && (
+                <span className="text-sm text-gray-500 dark:text-gray-400">
+                  Next: {nextBoss.name}
+                </span>
+              )}
+              {!nextBoss && (
+                <span className="text-sm text-green-600 dark:text-green-400">
+                  All bosses defeated!
+                </span>
+              )}
+            </div>
+            <span className="text-xs text-gray-400 dark:text-gray-500">
+              {defeatedBossIds.size}/{sortedBosses.length} defeated
+            </span>
+          </div>
+          {/* Badge row — gym leaders only */}
+          {sortedBosses.some((b) => b.bossType === 'gym_leader') && (
+            <div className="flex gap-2 flex-wrap">
+              {sortedBosses
+                .filter((b) => b.bossType === 'gym_leader')
+                .map((boss) => {
+                  const earned = defeatedBossIds.has(boss.id)
+                  return (
+                    <div
+                      key={boss.id}
+                      className={`flex flex-col items-center transition-opacity ${earned ? '' : 'opacity-30 grayscale'}`}
+                      title={`${boss.badgeName ?? boss.name}${earned ? ' (earned)' : ''}`}
+                    >
+                      {boss.badgeImageUrl ? (
+                        <img
+                          src={boss.badgeImageUrl}
+                          alt={boss.badgeName ?? boss.name}
+                          className="w-6 h-6"
+                        />
+                      ) : (
+                        <div className={`w-6 h-6 rounded-full border-2 flex items-center justify-center text-xs font-bold ${
+                          earned
+                            ? 'border-yellow-500 bg-yellow-100 dark:bg-yellow-900/40 text-yellow-700 dark:text-yellow-300'
+                            : 'border-gray-300 dark:border-gray-600 text-gray-400'
+                        }`}>
+                          {boss.order}
+                        </div>
+                      )}
+                    </div>
+                  )
+                })}
+            </div>
+          )}
+        </div>
+      )}
+
       {/* Rules */}
       <div className="mb-6">
         <h2 className="text-sm font-medium text-gray-500 dark:text-gray-400 mb-2">
@@ -813,71 +923,168 @@ export function RunEncounters() {
           </p>
         )}
         {filteredRoutes.map((route) => {
-          // Render as group if it has children
-          if (route.children.length > 0) {
-            return (
-              <RouteGroup
-                key={route.id}
-                group={route}
-                encounterByRoute={encounterByRoute}
-                isExpanded={expandedGroups.has(route.id)}
-                onToggleExpand={() => toggleGroup(route.id)}
-                onRouteClick={handleRouteClick}
-                filter={filter}
-                pinwheelClause={pinwheelClause}
-              />
-            )
+          // Collect all route IDs to check for boss cards after
+          const routeIds: number[] = route.children.length > 0
+            ? [route.id, ...route.children.map((c) => c.id)]
+            : [route.id]
+
+          // Find boss battles positioned after this route (or any of its children)
+          const bossesHere: BossBattle[] = []
+          for (const rid of routeIds) {
+            const b = bossesAfterRoute.get(rid)
+            if (b) bossesHere.push(...b)
           }
 
-          // Standalone route (no children)
-          const encounter = encounterByRoute.get(route.id)
-          const rs = getRouteStatus(encounter)
-          const si = statusIndicator[rs]
+          const routeElement = route.children.length > 0 ? (
+            <RouteGroup
+              key={route.id}
+              group={route}
+              encounterByRoute={encounterByRoute}
+              isExpanded={expandedGroups.has(route.id)}
+              onToggleExpand={() => toggleGroup(route.id)}
+              onRouteClick={handleRouteClick}
+              filter={filter}
+              pinwheelClause={pinwheelClause}
+            />
+          ) : (() => {
+            const encounter = encounterByRoute.get(route.id)
+            const rs = getRouteStatus(encounter)
+            const si = statusIndicator[rs]
+
+            return (
+              <button
+                key={route.id}
+                type="button"
+                onClick={() => handleRouteClick(route)}
+                className={`w-full flex items-center gap-3 px-4 py-3 rounded-lg text-left transition-colors hover:bg-gray-100 dark:hover:bg-gray-700/50 ${si.bg}`}
+              >
+                <span
+                  className={`w-2.5 h-2.5 rounded-full shrink-0 ${si.dot}`}
+                />
+                <div className="flex-1 min-w-0">
+                  <div className="text-sm font-medium text-gray-900 dark:text-gray-100">
+                    {route.name}
+                  </div>
+                  {encounter ? (
+                    <div className="flex items-center gap-2 mt-0.5">
+                      {encounter.pokemon.spriteUrl && (
+                        <img
+                          src={encounter.pokemon.spriteUrl}
+                          alt={encounter.pokemon.name}
+                          className="w-5 h-5"
+                        />
+                      )}
+                      <span className="text-xs text-gray-500 dark:text-gray-400 capitalize">
+                        {encounter.nickname ?? encounter.pokemon.name}
+                        {encounter.status === 'caught' &&
+                          encounter.faintLevel !== null &&
+                          (encounter.deathCause
+                            ? ` — ${encounter.deathCause}`
+                            : ' (dead)')}
+                      </span>
+                    </div>
+                  ) : route.encounterMethods.length > 0 && (
+                    <div className="flex flex-wrap gap-1 mt-0.5">
+                      {route.encounterMethods.map((m) => (
+                        <EncounterMethodBadge key={m} method={m} size="xs" />
+                      ))}
+                    </div>
+                  )}
+                </div>
+                <span className="text-xs text-gray-400 dark:text-gray-500 shrink-0">
+                  {si.label}
+                </span>
+              </button>
+            )
+          })()
 
           return (
-            <button
-              key={route.id}
-              type="button"
-              onClick={() => handleRouteClick(route)}
-              className={`w-full flex items-center gap-3 px-4 py-3 rounded-lg text-left transition-colors hover:bg-gray-100 dark:hover:bg-gray-700/50 ${si.bg}`}
-            >
-              <span
-                className={`w-2.5 h-2.5 rounded-full shrink-0 ${si.dot}`}
-              />
-              <div className="flex-1 min-w-0">
-                <div className="text-sm font-medium text-gray-900 dark:text-gray-100">
-                  {route.name}
-                </div>
-                {encounter ? (
-                  <div className="flex items-center gap-2 mt-0.5">
-                    {encounter.pokemon.spriteUrl && (
-                      <img
-                        src={encounter.pokemon.spriteUrl}
-                        alt={encounter.pokemon.name}
-                        className="w-5 h-5"
-                      />
+            <div key={route.id}>
+              {routeElement}
+              {/* Boss battle cards after this route */}
+              {bossesHere.map((boss) => {
+                const isDefeated = defeatedBossIds.has(boss.id)
+                const bossTypeLabel: Record<string, string> = {
+                  gym_leader: 'Gym Leader',
+                  elite_four: 'Elite Four',
+                  champion: 'Champion',
+                  rival: 'Rival',
+                  evil_team: 'Evil Team',
+                  other: 'Boss',
+                }
+                const bossTypeColors: Record<string, string> = {
+                  gym_leader: 'border-yellow-400 dark:border-yellow-600',
+                  elite_four: 'border-purple-400 dark:border-purple-600',
+                  champion: 'border-red-400 dark:border-red-600',
+                  rival: 'border-blue-400 dark:border-blue-600',
+                  evil_team: 'border-gray-500 dark:border-gray-400',
+                  other: 'border-gray-400 dark:border-gray-500',
+                }
+
+                return (
+                  <div
+                    key={`boss-${boss.id}`}
+                    className={`my-2 rounded-lg border-2 ${bossTypeColors[boss.bossType] ?? bossTypeColors.other} ${
+                      isDefeated ? 'bg-green-50/50 dark:bg-green-900/10' : 'bg-white dark:bg-gray-800'
+                    } px-4 py-3`}
+                  >
+                    <div className="flex items-start justify-between">
+                      <div className="flex items-center gap-3">
+                        {boss.spriteUrl && (
+                          <img src={boss.spriteUrl} alt={boss.name} className="w-10 h-10" />
+                        )}
+                        <div>
+                          <div className="flex items-center gap-2">
+                            <span className="text-sm font-semibold text-gray-900 dark:text-gray-100">
+                              {boss.name}
+                            </span>
+                            <span className="px-2 py-0.5 text-xs font-medium rounded-full bg-gray-100 dark:bg-gray-700 text-gray-600 dark:text-gray-300">
+                              {bossTypeLabel[boss.bossType] ?? boss.bossType}
+                            </span>
+                          </div>
+                          <p className="text-xs text-gray-500 dark:text-gray-400">
+                            {boss.location} &middot; Level Cap: {boss.levelCap}
+                          </p>
+                        </div>
+                      </div>
+                      <div>
+                        {isDefeated ? (
+                          <span className="inline-flex items-center gap-1 px-2 py-1 text-xs font-medium rounded-full bg-green-100 dark:bg-green-900/40 text-green-700 dark:text-green-300">
+                            Defeated &#10003;
+                          </span>
+                        ) : isActive ? (
+                          <button
+                            onClick={() => setSelectedBoss(boss)}
+                            className="px-3 py-1 text-xs font-medium rounded-full bg-blue-600 text-white hover:bg-blue-700 transition-colors"
+                          >
+                            Battle
+                          </button>
+                        ) : null}
+                      </div>
+                    </div>
+                    {/* Boss pokemon team */}
+                    {boss.pokemon.length > 0 && (
+                      <div className="flex gap-2 mt-2 flex-wrap">
+                        {boss.pokemon
+                          .sort((a, b) => a.order - b.order)
+                          .map((bp) => (
+                            <div key={bp.id} className="flex items-center gap-1">
+                              {bp.pokemon.spriteUrl ? (
+                                <img src={bp.pokemon.spriteUrl} alt={bp.pokemon.name} className="w-6 h-6" />
+                              ) : (
+                                <div className="w-6 h-6 bg-gray-200 dark:bg-gray-700 rounded-full" />
+                              )}
+                              <span className="text-xs text-gray-500 dark:text-gray-400">
+                                {bp.level}
+                              </span>
+                            </div>
+                          ))}
+                      </div>
                     )}
-                    <span className="text-xs text-gray-500 dark:text-gray-400 capitalize">
-                      {encounter.nickname ?? encounter.pokemon.name}
-                      {encounter.status === 'caught' &&
-                        encounter.faintLevel !== null &&
-                        (encounter.deathCause
-                          ? ` — ${encounter.deathCause}`
-                          : ' (dead)')}
-                    </span>
                   </div>
-                ) : route.encounterMethods.length > 0 && (
-                  <div className="flex flex-wrap gap-1 mt-0.5">
-                    {route.encounterMethods.map((m) => (
-                      <EncounterMethodBadge key={m} method={m} size="xs" />
-                    ))}
-                  </div>
-                )}
-              </div>
-              <span className="text-xs text-gray-400 dark:text-gray-500 shrink-0">
-                {si.label}
-              </span>
-            </button>
+                )
+              })}
+            </div>
           )
         })}
       </div>
@@ -923,6 +1130,20 @@ export function RunEncounters() {
         />
       )}
 
+      {/* Boss Defeat Modal */}
+      {selectedBoss && (
+        <BossDefeatModal
+          boss={selectedBoss}
+          onSubmit={(data) => {
+            createBossResult.mutate(data, {
+              onSuccess: () => setSelectedBoss(null),
+            })
+          }}
+          onClose={() => setSelectedBoss(null)}
+          isPending={createBossResult.isPending}
+        />
+      )}
+
       {/* End Run Modal */}
       {showEndRun && (
         <EndRunModal
diff --git a/frontend/src/pages/admin/AdminGameDetail.tsx b/frontend/src/pages/admin/AdminGameDetail.tsx
index 5c901bb..a939da2 100644
--- a/frontend/src/pages/admin/AdminGameDetail.tsx
+++ b/frontend/src/pages/admin/AdminGameDetail.tsx
@@ -18,16 +18,24 @@ import {
 import { CSS } from '@dnd-kit/utilities'
 import { RouteFormModal } from '../../components/admin/RouteFormModal'
 import { DeleteConfirmModal } from '../../components/admin/DeleteConfirmModal'
+import { BossBattleFormModal } from '../../components/admin/BossBattleFormModal'
+import { BossTeamEditor } from '../../components/admin/BossTeamEditor'
 import { useGame } from '../../hooks/useGames'
+import { useGameBosses } from '../../hooks/useBosses'
 import {
   useCreateRoute,
   useUpdateRoute,
   useDeleteRoute,
   useReorderRoutes,
+  useCreateBossBattle,
+  useUpdateBossBattle,
+  useDeleteBossBattle,
+  useSetBossTeam,
 } from '../../hooks/useAdmin'
 import { exportGameRoutes } from '../../api/admin'
 import { downloadJson } from '../../utils/download'
-import type { Route as GameRoute, CreateRouteInput, UpdateRouteInput } from '../../types'
+import type { Route as GameRoute, CreateRouteInput, UpdateRouteInput, BossBattle } from '../../types'
+import type { CreateBossBattleInput, UpdateBossBattleInput } from '../../types/admin'
 
 function SortableRouteRow({
   route,
@@ -105,10 +113,18 @@ export function AdminGameDetail() {
   const updateRoute = useUpdateRoute(id)
   const deleteRoute = useDeleteRoute(id)
   const reorderRoutes = useReorderRoutes(id)
+  const { data: bosses } = useGameBosses(id)
+  const createBoss = useCreateBossBattle(id)
+  const updateBoss = useUpdateBossBattle(id)
+  const deleteBoss = useDeleteBossBattle(id)
 
   const [showCreate, setShowCreate] = useState(false)
   const [editing, setEditing] = useState<GameRoute | null>(null)
   const [deleting, setDeleting] = useState<GameRoute | null>(null)
+  const [showCreateBoss, setShowCreateBoss] = useState(false)
+  const [editingBoss, setEditingBoss] = useState<BossBattle | null>(null)
+  const [deletingBoss, setDeletingBoss] = useState<BossBattle | null>(null)
+  const [editingTeam, setEditingTeam] = useState<BossBattle | null>(null)
 
   const sensors = useSensors(
     useSensor(PointerSensor, { activationConstraint: { distance: 5 } }),
@@ -268,6 +284,168 @@ export function AdminGameDetail() {
           isDeleting={deleteRoute.isPending}
         />
       )}
+
+      {/* Boss Battles Section */}
+      <div className="mt-10">
+        <div className="flex justify-between items-center mb-4">
+          <h3 className="text-lg font-medium">Boss Battles ({bosses?.length ?? 0})</h3>
+          <button
+            onClick={() => setShowCreateBoss(true)}
+            className="px-4 py-2 text-sm font-medium rounded-md bg-blue-600 text-white hover:bg-blue-700"
+          >
+            Add Boss Battle
+          </button>
+        </div>
+
+        {!bosses || bosses.length === 0 ? (
+          <div className="text-center py-8 text-gray-500 dark:text-gray-400 border border-gray-200 dark:border-gray-700 rounded-lg">
+            No boss battles yet. Add one to get started.
+          </div>
+        ) : (
+          <div className="border border-gray-200 dark:border-gray-700 rounded-lg overflow-hidden">
+            <div className="overflow-x-auto">
+              <table className="min-w-full divide-y divide-gray-200 dark:divide-gray-700">
+                <thead className="bg-gray-50 dark:bg-gray-800">
+                  <tr>
+                    <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider w-16">
+                      Order
+                    </th>
+                    <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">
+                      Name
+                    </th>
+                    <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">
+                      Type
+                    </th>
+                    <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">
+                      Location
+                    </th>
+                    <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider w-20">
+                      Lv Cap
+                    </th>
+                    <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider w-16">
+                      Team
+                    </th>
+                    <th className="px-4 py-3 text-left text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider w-40">
+                      Actions
+                    </th>
+                  </tr>
+                </thead>
+                <tbody className="bg-white dark:bg-gray-900 divide-y divide-gray-200 dark:divide-gray-700">
+                  {bosses.map((boss) => (
+                    <tr key={boss.id} className="hover:bg-gray-50 dark:hover:bg-gray-800">
+                      <td className="px-4 py-3 text-sm whitespace-nowrap">{boss.order}</td>
+                      <td className="px-4 py-3 text-sm whitespace-nowrap font-medium">{boss.name}</td>
+                      <td className="px-4 py-3 text-sm whitespace-nowrap capitalize">
+                        {boss.bossType.replace('_', ' ')}
+                      </td>
+                      <td className="px-4 py-3 text-sm whitespace-nowrap">{boss.location}</td>
+                      <td className="px-4 py-3 text-sm whitespace-nowrap">{boss.levelCap}</td>
+                      <td className="px-4 py-3 text-sm whitespace-nowrap">{boss.pokemon.length}</td>
+                      <td className="px-4 py-3 text-sm whitespace-nowrap">
+                        <div className="flex gap-2">
+                          <button
+                            onClick={() => setEditingTeam(boss)}
+                            className="text-green-600 hover:text-green-800 dark:text-green-400 text-sm"
+                          >
+                            Team
+                          </button>
+                          <button
+                            onClick={() => setEditingBoss(boss)}
+                            className="text-blue-600 hover:text-blue-800 dark:text-blue-400 text-sm"
+                          >
+                            Edit
+                          </button>
+                          <button
+                            onClick={() => setDeletingBoss(boss)}
+                            className="text-red-600 hover:text-red-800 dark:text-red-400 text-sm"
+                          >
+                            Delete
+                          </button>
+                        </div>
+                      </td>
+                    </tr>
+                  ))}
+                </tbody>
+              </table>
+            </div>
+          </div>
+        )}
+      </div>
+
+      {/* Boss Battle Modals */}
+      {showCreateBoss && (
+        <BossBattleFormModal
+          routes={routes}
+          nextOrder={bosses ? Math.max(0, ...bosses.map((b) => b.order)) + 1 : 1}
+          onSubmit={(data) =>
+            createBoss.mutate(data as CreateBossBattleInput, {
+              onSuccess: () => setShowCreateBoss(false),
+            })
+          }
+          onClose={() => setShowCreateBoss(false)}
+          isSubmitting={createBoss.isPending}
+        />
+      )}
+
+      {editingBoss && (
+        <BossBattleFormModal
+          boss={editingBoss}
+          routes={routes}
+          nextOrder={editingBoss.order}
+          onSubmit={(data) =>
+            updateBoss.mutate(
+              { bossId: editingBoss.id, data: data as UpdateBossBattleInput },
+              { onSuccess: () => setEditingBoss(null) },
+            )
+          }
+          onClose={() => setEditingBoss(null)}
+          isSubmitting={updateBoss.isPending}
+        />
+      )}
+
+      {deletingBoss && (
+        <DeleteConfirmModal
+          title={`Delete ${deletingBoss.name}?`}
+          message="This will permanently delete this boss battle and its pokemon team."
+          onConfirm={() =>
+            deleteBoss.mutate(deletingBoss.id, {
+              onSuccess: () => setDeletingBoss(null),
+            })
+          }
+          onCancel={() => setDeletingBoss(null)}
+          isDeleting={deleteBoss.isPending}
+        />
+      )}
+
+      {editingTeam && (
+        <BossTeamEditorWrapper
+          gameId={id}
+          boss={editingTeam}
+          onClose={() => setEditingTeam(null)}
+        />
+      )}
     </div>
   )
 }
+
+function BossTeamEditorWrapper({
+  gameId,
+  boss,
+  onClose,
+}: {
+  gameId: number
+  boss: BossBattle
+  onClose: () => void
+}) {
+  const setBossTeam = useSetBossTeam(gameId, boss.id)
+  return (
+    <BossTeamEditor
+      boss={boss}
+      onSave={(team) =>
+        setBossTeam.mutate(team, { onSuccess: onClose })
+      }
+      onClose={onClose}
+      isSaving={setBossTeam.isPending}
+    />
+  )
+}
diff --git a/frontend/src/types/admin.ts b/frontend/src/types/admin.ts
index 0c51032..5951111 100644
--- a/frontend/src/types/admin.ts
+++ b/frontend/src/types/admin.ts
@@ -119,3 +119,34 @@ export interface UpdateEvolutionInput {
   condition?: string | null
   region?: string | null
 }
+
+// Boss battles admin
+export interface CreateBossBattleInput {
+  name: string
+  bossType: string
+  badgeName?: string | null
+  badgeImageUrl?: string | null
+  levelCap: number
+  order: number
+  afterRouteId?: number | null
+  location: string
+  spriteUrl?: string | null
+}
+
+export interface UpdateBossBattleInput {
+  name?: string
+  bossType?: string
+  badgeName?: string | null
+  badgeImageUrl?: string | null
+  levelCap?: number
+  order?: number
+  afterRouteId?: number | null
+  location?: string
+  spriteUrl?: string | null
+}
+
+export interface BossPokemonInput {
+  pokemonId: number
+  level: number
+  order: number
+}
diff --git a/frontend/src/types/game.ts b/frontend/src/types/game.ts
index f7c9183..5834c09 100644
--- a/frontend/src/types/game.ts
+++ b/frontend/src/types/game.ts
@@ -127,6 +127,47 @@ export interface UpdateEncounterInput {
   currentPokemonId?: number
 }
 
+// Boss battles
+export type BossType = 'gym_leader' | 'elite_four' | 'champion' | 'rival' | 'evil_team' | 'other'
+
+export interface BossPokemon {
+  id: number
+  pokemonId: number
+  level: number
+  order: number
+  pokemon: Pokemon
+}
+
+export interface BossBattle {
+  id: number
+  gameId: number
+  name: string
+  bossType: BossType
+  badgeName: string | null
+  badgeImageUrl: string | null
+  levelCap: number
+  order: number
+  afterRouteId: number | null
+  location: string
+  spriteUrl: string | null
+  pokemon: BossPokemon[]
+}
+
+export interface BossResult {
+  id: number
+  runId: number
+  bossBattleId: number
+  result: 'won' | 'lost'
+  attempts: number
+  completedAt: string | null
+}
+
+export interface CreateBossResultInput {
+  bossBattleId: number
+  result: 'won' | 'lost'
+  attempts?: number
+}
+
 // Re-export for convenience
 import type { NuzlockeRules } from './rules'
 export type { NuzlockeRules }