Add hierarchical route grouping for multi-area locations

Locations like Mt. Moon (with 1F, B1F, B2F floors) are now grouped so
only one encounter can be logged per location group, enforcing Nuzlocke
first-encounter rules correctly.

- Add parent_route_id column with self-referential FK to routes table
- Add parent/children relationships on Route model
- Update games API to return hierarchical route structure
- Add validation in encounters API to prevent parent route encounters
  and duplicate encounters within sibling routes (409 conflict)
- Update frontend with collapsible RouteGroup component
- Auto-derive route groups from PokeAPI location/location-area structure
- Regenerate seed data with 70 parent routes and 315 child routes

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.beans/nuzlocke-tracker-u7i9--combine-sub-areas-into-single-locations.md

@@ -1,19 +1,64 @@
 ---
 # nuzlocke-tracker-u7i9
 title: Combine sub-areas into single locations
-status: todo
+status: completed
 type: feature
+priority: normal
 created_at: 2026-02-05T14:27:13Z
-updated_at: 2026-02-05T14:27:13Z
+updated_at: 2026-02-06T09:56:11Z
 parent: nuzlocke-tracker-f5ob
 ---
 
-Some game locations have multiple encounter tables (e.g. Mount Moon 1F, Mount Moon B1F, Mount Moon B2F) but are treated as a single location for Nuzlocke first-encounter rules. 
+Some game locations have multiple encounter tables (e.g. Mount Moon 1F, Mount Moon B1F, Mount Moon B2F) but are treated as a single location for Nuzlocke first-encounter rules.
 
 Needs a concept of 'location groups' — a parent location that contains multiple sub-areas, each with their own encounter table. For Nuzlocke purposes, the first encounter in *any* sub-area of the group counts as that location's encounter.
 
+## Implementation Summary
+
+Added hierarchical route grouping so locations like Mt. Moon (with floors 1F, B1F, B2F) are treated as a single location for Nuzlocke first-encounter rules. The first encounter in ANY sub-area counts as that location's encounter.
+
+### Changes Made
+
+1. **Database Migration** (`c3d4e5f6a7b8_add_route_grouping.py`)
+   - Added nullable `parent_route_id` column with self-referential FK (CASCADE delete)
+
+2. **Backend Model** (`backend/src/app/models/route.py`)
+   - Added `parent_route_id` field
+   - Added self-referential `parent` and `children` relationships
+
+3. **Backend Schemas** (`backend/src/app/schemas/game.py`)
+   - Added `parent_route_id` to `RouteResponse`, `RouteCreate`, `RouteUpdate`
+   - Added `RouteWithChildrenResponse` with nested children
+
+4. **Backend API - Games** (`backend/src/app/api/games.py`)
+   - Updated `list_game_routes` to support hierarchical response (default) or flat list (`?flat=true`)
+
+5. **Backend API - Encounters** (`backend/src/app/api/encounters.py`)
+   - Added validation: cannot create encounter on parent route (400 error)
+   - Added validation: cannot create encounter if sibling already has one (409 error)
+
+6. **Frontend Types** (`frontend/src/types/game.ts`)
+   - Added `parentRouteId` to `Route` interface
+   - Added `RouteWithChildren` interface
+
+7. **Frontend Page** (`frontend/src/pages/RunEncounters.tsx`)
+   - Added `organizeRoutes()` helper to build hierarchy from flat list
+   - Added `getGroupEncounter()` to check if any child has an encounter
+   - Updated progress counter to count groups (not individual sub-routes)
+   - Added collapsible `RouteGroup` component
+   - Sibling routes are disabled after one has an encounter
+
+8. **Seed Data** (`backend/src/app/seeds/fetch_pokeapi.py`)
+   - Updated to automatically detect grouped locations from PokeAPI's location/location-area structure
+   - Parent routes have empty encounters; children have actual encounters
+   - 70 parent routes with 315 child routes across all games
+
+9. **Seed Loader** (`backend/src/app/seeds/loader.py`, `run.py`)
+   - Updated `upsert_routes` to handle hierarchical structure with parent_route_id
+   - Updated seed runner to process child route encounters
+
 ## Considerations
-- Data model: add a parent_route_id or location_group concept to the Route model
-- Seed data: identify which routes should be grouped (may need manual curation per game)
-- Encounter tracking: when logging an encounter in a sub-area, mark the whole group as visited
-- Route list UI: show grouped locations as collapsible sections
+- [x] Data model: add a parent_route_id or location_group concept to the Route model
+- [x] Seed data: identify which routes should be grouped (automatically derived from PokeAPI location/area structure)
+- [x] Encounter tracking: when logging an encounter in a sub-area, mark the whole group as visited
+- [x] Route list UI: show grouped locations as collapsible sections

backend/src/app/alembic/versions/c3d4e5f6a7b8_add_route_grouping.py

@@ -0,0 +1,35 @@
+"""add parent_route_id for route grouping
+
+Revision ID: c3d4e5f6a7b8
+Revises: b2c3d4e5f6a7
+Create Date: 2026-02-06 12:00:00.000000
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision: str = 'c3d4e5f6a7b8'
+down_revision: Union[str, Sequence[str], None] = 'b2c3d4e5f6a7'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        'routes',
+        sa.Column(
+            'parent_route_id',
+            sa.Integer(),
+            sa.ForeignKey('routes.id', ondelete='CASCADE'),
+            nullable=True,
+            index=True,
+        ),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column('routes', 'parent_route_id')

backend/src/app/api/encounters.py

@@ -1,7 +1,7 @@
 from fastapi import APIRouter, Depends, HTTPException, Response
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
-from sqlalchemy.orm import joinedload
+from sqlalchemy.orm import joinedload, selectinload
 
 from app.core.database import get_session
 from app.models.encounter import Encounter
@@ -33,11 +33,45 @@ async def create_encounter(
     if run is None:
         raise HTTPException(status_code=404, detail="Run not found")
 
-    # Validate route exists
-    route = await session.get(Route, data.route_id)
+    # Validate route exists and load its children
+    result = await session.execute(
+        select(Route)
+        .where(Route.id == data.route_id)
+        .options(selectinload(Route.children))
+    )
+    route = result.scalar_one_or_none()
     if route is None:
         raise HTTPException(status_code=404, detail="Route not found")
 
+    # Cannot create encounter on a parent route (routes with children)
+    if route.children:
+        raise HTTPException(
+            status_code=400,
+            detail="Cannot create encounter on a parent route. Use a child route instead.",
+        )
+
+    # If this route has a parent, check if any sibling already has an encounter
+    if route.parent_route_id is not None:
+        # Get all sibling route IDs (routes with same parent, including this one)
+        siblings_result = await session.execute(
+            select(Route.id).where(Route.parent_route_id == route.parent_route_id)
+        )
+        sibling_ids = [r for r in siblings_result.scalars().all()]
+
+        # Check if any sibling already has an encounter in this run
+        existing_encounter = await session.execute(
+            select(Encounter)
+            .where(
+                Encounter.run_id == run_id,
+                Encounter.route_id.in_(sibling_ids),
+            )
+        )
+        if existing_encounter.scalar_one_or_none() is not None:
+            raise HTTPException(
+                status_code=409,
+                detail="This location group already has an encounter. Only one encounter per location group is allowed.",
+            )
+
     # Validate pokemon exists
     pokemon = await session.get(Pokemon, data.pokemon_id)
     if pokemon is None:

backend/src/app/api/games.py

@@ -15,6 +15,7 @@ from app.schemas.game import (
     RouteReorderRequest,
     RouteResponse,
     RouteUpdate,
+    RouteWithChildrenResponse,
 )
 
 router = APIRouter()
@@ -42,10 +43,21 @@ async def get_game(game_id: int, session: AsyncSession = Depends(get_session)):
     return game
 
 
-@router.get("/{game_id}/routes", response_model=list[RouteResponse])
+@router.get(
+    "/{game_id}/routes",
+    response_model=list[RouteWithChildrenResponse] | list[RouteResponse],
+)
 async def list_game_routes(
-    game_id: int, session: AsyncSession = Depends(get_session)
+    game_id: int,
+    flat: bool = False,
+    session: AsyncSession = Depends(get_session),
 ):
+    """
+    List routes for a game.
+
+    By default, returns a hierarchical structure with top-level routes containing
+    nested children. Use `flat=True` to get a flat list of all routes.
+    """
     # Verify game exists
     game = await session.get(Game, game_id)
     if game is None:
@@ -56,7 +68,36 @@ async def list_game_routes(
         .where(Route.game_id == game_id)
         .order_by(Route.order)
     )
-    return result.scalars().all()
+    all_routes = result.scalars().all()
+
+    if flat:
+        return all_routes
+
+    # Build hierarchical structure
+    # Group children by parent_route_id
+    children_by_parent: dict[int, list[Route]] = {}
+    top_level_routes: list[Route] = []
+
+    for route in all_routes:
+        if route.parent_route_id is None:
+            top_level_routes.append(route)
+        else:
+            children_by_parent.setdefault(route.parent_route_id, []).append(route)
+
+    # Build response with nested children
+    response = []
+    for route in top_level_routes:
+        route_dict = {
+            "id": route.id,
+            "name": route.name,
+            "game_id": route.game_id,
+            "order": route.order,
+            "parent_route_id": route.parent_route_id,
+            "children": children_by_parent.get(route.id, []),
+        }
+        response.append(route_dict)
+
+    return response
 
 
 # --- Admin endpoints ---

backend/src/app/models/route.py

@@ -14,6 +14,9 @@ class Route(Base):
     name: Mapped[str] = mapped_column(String(100))
     game_id: Mapped[int] = mapped_column(ForeignKey("games.id"), index=True)
     order: Mapped[int] = mapped_column(SmallInteger)
+    parent_route_id: Mapped[int | None] = mapped_column(
+        ForeignKey("routes.id", ondelete="CASCADE"), index=True, default=None
+    )
 
     game: Mapped["Game"] = relationship(back_populates="routes")
     route_encounters: Mapped[list["RouteEncounter"]] = relationship(
@@ -21,5 +24,13 @@ class Route(Base):
     )
     encounters: Mapped[list["Encounter"]] = relationship(back_populates="route")
 
+    # Self-referential relationships for route grouping
+    parent: Mapped["Route | None"] = relationship(
+        back_populates="children", remote_side=[id]
+    )
+    children: Mapped[list["Route"]] = relationship(
+        back_populates="parent", cascade="all, delete-orphan"
+    )
+
     def __repr__(self) -> str:
         return f"<Route(id={self.id}, name='{self.name}')>"

backend/src/app/schemas/game.py

@@ -6,6 +6,7 @@ class RouteResponse(CamelModel):
     name: str
     game_id: int
     order: int
+    parent_route_id: int | None = None
 
 
 class GameResponse(CamelModel):
@@ -18,6 +19,10 @@ class GameResponse(CamelModel):
     release_year: int | None
 
 
+class RouteWithChildrenResponse(RouteResponse):
+    children: list[RouteResponse] = []
+
+
 class GameDetailResponse(GameResponse):
     routes: list[RouteResponse] = []
 
@@ -46,11 +51,13 @@ class GameUpdate(CamelModel):
 class RouteCreate(CamelModel):
     name: str
     order: int
+    parent_route_id: int | None = None
 
 
 class RouteUpdate(CamelModel):
     name: str | None = None
     order: int | None = None
+    parent_route_id: int | None = None
 
 
 class RouteReorderItem(CamelModel):

backend/src/app/seeds/fetch_pokeapi.py

@@ -187,7 +187,11 @@ def aggregate_encounters(raw_encounters: list[dict]) -> list[dict]:
 
 
 def process_version(version_name: str, vg_info: dict) -> list[dict]:
-    """Process all locations for a specific game version."""
+    """Process all locations for a specific game version.
+
+    Creates hierarchical route structure where locations with multiple areas
+    become parent routes with child routes for each area.
+    """
     print(f"\n--- Processing {version_name} ---")
 
     region = load_resource("region", vg_info["region_id"])
@@ -230,8 +234,38 @@ def process_version(version_name: str, vg_info: dict) -> list[dict]:
             else:
                 all_encounters.extend(encounters)
 
-        # Area-specific encounters become separate routes
-        if area_specific:
+        # If we have multiple area-specific encounters, create a parent route
+        # with child routes for each area (hierarchical grouping)
+        if area_specific and len(area_specific) > 1:
+            # Create parent route (no encounters - just a logical grouping)
+            parent_order = order
+            order += 1
+
+            child_routes = []
+            for area_suffix, area_encs in area_specific.items():
+                aggregated = aggregate_encounters(area_encs)
+                if aggregated:
+                    route_name = f"{display_name} ({area_suffix})"
+                    for enc in aggregated:
+                        all_pokemon_dex.add(enc["national_dex"])
+                    child_routes.append({
+                        "name": route_name,
+                        "order": order,
+                        "encounters": aggregated,
+                    })
+                    order += 1
+
+            # Only add parent if we have child routes
+            if child_routes:
+                routes.append({
+                    "name": display_name,
+                    "order": parent_order,
+                    "encounters": [],  # Parent routes have no encounters
+                    "children": child_routes,
+                })
+
+        elif area_specific:
+            # Only one area-specific route - don't create parent/child, just use suffix
             for area_suffix, area_encs in area_specific.items():
                 aggregated = aggregate_encounters(area_encs)
                 if aggregated:
@@ -245,6 +279,7 @@ def process_version(version_name: str, vg_info: dict) -> list[dict]:
                     })
                     order += 1
 
+        # Non-area-specific encounters (or single area without suffix)
         if all_encounters:
             aggregated = aggregate_encounters(all_encounters)
             if aggregated:
@@ -257,8 +292,13 @@ def process_version(version_name: str, vg_info: dict) -> list[dict]:
                 })
                 order += 1
 
-    print(f"  Routes with encounters: {len(routes)}")
-    total_enc = sum(len(r["encounters"]) for r in routes)
+    # Count routes including children
+    total_routes = sum(1 + len(r.get("children", [])) for r in routes)
+    print(f"  Routes with encounters: {total_routes}")
+    total_enc = sum(
+        len(r["encounters"]) + sum(len(c["encounters"]) for c in r.get("children", []))
+        for r in routes
+    )
     print(f"  Total encounter entries: {total_enc}")
 
     return routes

backend/src/app/seeds/loader.py

@@ -66,20 +66,54 @@ async def upsert_routes(
     game_id: int,
     routes: list[dict],
 ) -> dict[str, int]:
-    """Upsert route records for a game, return {name: id} mapping."""
+    """Upsert route records for a game, return {name: id} mapping.
+
+    Handles hierarchical routes: routes with 'children' are parent routes,
+    and their children get parent_route_id set accordingly.
+    """
+    # First pass: upsert all parent routes (without parent_route_id)
     for route in routes:
         stmt = insert(Route).values(
             name=route["name"],
             game_id=game_id,
             order=route["order"],
+            parent_route_id=None,  # Parent routes have no parent
         ).on_conflict_do_update(
             constraint="uq_routes_game_name",
-            set_={"order": route["order"]},
+            set_={"order": route["order"], "parent_route_id": None},
         )
         await session.execute(stmt)
 
     await session.flush()
 
+    # Get mapping of parent routes
+    result = await session.execute(
+        select(Route.name, Route.id).where(Route.game_id == game_id)
+    )
+    name_to_id = {row.name: row.id for row in result}
+
+    # Second pass: upsert child routes with parent_route_id
+    for route in routes:
+        children = route.get("children", [])
+        if not children:
+            continue
+
+        parent_id = name_to_id[route["name"]]
+        for child in children:
+            stmt = insert(Route).values(
+                name=child["name"],
+                game_id=game_id,
+                order=child["order"],
+                parent_route_id=parent_id,
+            ).on_conflict_do_update(
+                constraint="uq_routes_game_name",
+                set_={"order": child["order"], "parent_route_id": parent_id},
+            )
+            await session.execute(stmt)
+
+    await session.flush()
+
+    # Return full mapping including children
     result = await session.execute(
         select(Route.name, Route.id).where(Route.game_id == game_id)
     )

backend/src/app/seeds/run.py

@@ -66,10 +66,24 @@ async def seed():
                         print(f"  Warning: route '{route['name']}' not found")
                         continue
 
-                    enc_count = await upsert_route_encounters(
-                        session, route_id, route["encounters"], dex_to_id
-                    )
-                    total_encounters += enc_count
+                    # Parent routes may have empty encounters
+                    if route["encounters"]:
+                        enc_count = await upsert_route_encounters(
+                            session, route_id, route["encounters"], dex_to_id
+                        )
+                        total_encounters += enc_count
+
+                    # Handle child routes
+                    for child in route.get("children", []):
+                        child_id = route_map.get(child["name"])
+                        if child_id is None:
+                            print(f"  Warning: child route '{child['name']}' not found")
+                            continue
+
+                        enc_count = await upsert_route_encounters(
+                            session, child_id, child["encounters"], dex_to_id
+                        )
+                        total_encounters += enc_count
 
                 print(f"  {game_slug}: {len(route_map)} routes")
 

frontend/src/api/games.ts

@@ -14,7 +14,9 @@ export function getGame(id: number): Promise<GameDetail> {
 }
 
 export function getGameRoutes(gameId: number): Promise<Route[]> {
-  return api.get(`/games/${gameId}/routes`)
+  // Use flat=true to get all routes in a flat list
+  // The frontend organizes them into hierarchy based on parentRouteId
+  return api.get(`/games/${gameId}/routes?flat=true`)
 }
 
 export function getRoutePokemon(routeId: number): Promise<RouteEncounterDetail[]> {

frontend/src/pages/RunEncounters.tsx

@@ -1,10 +1,15 @@
-import { useState } from 'react'
+import { useState, useMemo } from 'react'
 import { useParams, Link } from 'react-router-dom'
 import { useRun } from '../hooks/useRuns'
 import { useGameRoutes } from '../hooks/useGames'
 import { useCreateEncounter, useUpdateEncounter } from '../hooks/useEncounters'
 import { EncounterModal } from '../components'
-import type { Route, EncounterDetail, EncounterStatus } from '../types'
+import type {
+  Route,
+  RouteWithChildren,
+  EncounterDetail,
+  EncounterStatus,
+} from '../types'
 
 type RouteStatus = 'caught' | 'fainted' | 'missed' | 'none'
 
@@ -35,6 +40,175 @@ const statusIndicator: Record<
   none: { dot: 'bg-gray-300 dark:bg-gray-600', label: '', bg: '' },
 }
 
+/**
+ * Organize flat routes into hierarchical structure.
+ * Routes with parentRouteId are grouped under their parent.
+ */
+function organizeRoutes(routes: Route[]): RouteWithChildren[] {
+  const childrenByParent = new Map<number, Route[]>()
+  const topLevel: Route[] = []
+
+  for (const route of routes) {
+    if (route.parentRouteId === null) {
+      topLevel.push(route)
+    } else {
+      const children = childrenByParent.get(route.parentRouteId) ?? []
+      children.push(route)
+      childrenByParent.set(route.parentRouteId, children)
+    }
+  }
+
+  return topLevel.map((route) => ({
+    ...route,
+    children: childrenByParent.get(route.id) ?? [],
+  }))
+}
+
+/**
+ * Check if any child route in a group has an encounter.
+ * Returns the encounter if found, null otherwise.
+ */
+function getGroupEncounter(
+  group: RouteWithChildren,
+  encounterByRoute: Map<number, EncounterDetail>,
+): EncounterDetail | null {
+  for (const child of group.children) {
+    const enc = encounterByRoute.get(child.id)
+    if (enc) return enc
+  }
+  return null
+}
+
+interface RouteGroupProps {
+  group: RouteWithChildren
+  encounterByRoute: Map<number, EncounterDetail>
+  isExpanded: boolean
+  onToggleExpand: () => void
+  onRouteClick: (route: Route) => void
+  filter: 'all' | RouteStatus
+}
+
+function RouteGroup({
+  group,
+  encounterByRoute,
+  isExpanded,
+  onToggleExpand,
+  onRouteClick,
+  filter,
+}: RouteGroupProps) {
+  const groupEncounter = getGroupEncounter(group, encounterByRoute)
+  const groupStatus = groupEncounter ? groupEncounter.status : 'none'
+  const si = statusIndicator[groupStatus]
+
+  // For groups, check if it matches the filter
+  if (filter !== 'all' && groupStatus !== filter) {
+    return null
+  }
+
+  const hasGroupEncounter = groupEncounter !== null
+
+  return (
+    <div className="border border-gray-200 dark:border-gray-700 rounded-lg overflow-hidden">
+      {/* Group header */}
+      <button
+        type="button"
+        onClick={onToggleExpand}
+        className={`w-full flex items-center gap-3 px-4 py-3 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 flex items-center gap-2">
+            {group.name}
+            <span className="text-xs text-gray-400 dark:text-gray-500">
+              ({group.children.length} areas)
+            </span>
+          </div>
+          {groupEncounter && (
+            <div className="flex items-center gap-2 mt-0.5">
+              {groupEncounter.pokemon.spriteUrl && (
+                <img
+                  src={groupEncounter.pokemon.spriteUrl}
+                  alt={groupEncounter.pokemon.name}
+                  className="w-5 h-5"
+                />
+              )}
+              <span className="text-xs text-gray-500 dark:text-gray-400 capitalize">
+                {groupEncounter.nickname ?? groupEncounter.pokemon.name}
+                {groupEncounter.status === 'caught' &&
+                  groupEncounter.faintLevel !== null &&
+                  (groupEncounter.deathCause
+                    ? ` — ${groupEncounter.deathCause}`
+                    : ' (dead)')}
+              </span>
+            </div>
+          )}
+        </div>
+        <span className="text-xs text-gray-400 dark:text-gray-500 shrink-0">
+          {si.label}
+        </span>
+        <svg
+          className={`w-4 h-4 text-gray-400 transition-transform ${isExpanded ? 'rotate-180' : ''}`}
+          fill="none"
+          stroke="currentColor"
+          viewBox="0 0 24 24"
+        >
+          <path
+            strokeLinecap="round"
+            strokeLinejoin="round"
+            strokeWidth={2}
+            d="M19 9l-7 7-7-7"
+          />
+        </svg>
+      </button>
+
+      {/* Expanded children */}
+      {isExpanded && (
+        <div className="border-t border-gray-200 dark:border-gray-700 bg-gray-50/50 dark:bg-gray-800/50">
+          {group.children.map((child) => {
+            const childEncounter = encounterByRoute.get(child.id)
+            const childStatus = getRouteStatus(childEncounter)
+            const childSi = statusIndicator[childStatus]
+            const isDisabled = hasGroupEncounter && !childEncounter
+
+            return (
+              <button
+                key={child.id}
+                type="button"
+                onClick={() => !isDisabled && onRouteClick(child)}
+                disabled={isDisabled}
+                className={`w-full flex items-center gap-3 px-4 py-2 pl-8 text-left transition-colors ${
+                  isDisabled
+                    ? 'opacity-50 cursor-not-allowed'
+                    : 'hover:bg-gray-100 dark:hover:bg-gray-700/50'
+                } ${childSi.bg}`}
+              >
+                <span
+                  className={`w-2 h-2 rounded-full shrink-0 ${childSi.dot}`}
+                />
+                <div className="flex-1 min-w-0">
+                  <div className="text-sm text-gray-700 dark:text-gray-300">
+                    {child.name}
+                  </div>
+                </div>
+                {childEncounter && (
+                  <span className="text-xs text-gray-400 dark:text-gray-500">
+                    {childSi.label}
+                  </span>
+                )}
+                {isDisabled && (
+                  <span className="text-xs text-gray-400 dark:text-gray-500 italic">
+                    (locked)
+                  </span>
+                )}
+              </button>
+            )
+          })}
+        </div>
+      )}
+    </div>
+  )
+}
+
 export function RunEncounters() {
   const { runId } = useParams<{ runId: string }>()
   const runIdNum = Number(runId)
@@ -49,6 +223,13 @@ export function RunEncounters() {
   const [editingEncounter, setEditingEncounter] =
     useState<EncounterDetail | null>(null)
   const [filter, setFilter] = useState<'all' | RouteStatus>('all')
+  const [expandedGroups, setExpandedGroups] = useState<Set<number>>(new Set())
+
+  // Organize routes into hierarchical structure
+  const organizedRoutes = useMemo(() => {
+    if (!routes) return []
+    return organizeRoutes(routes)
+  }, [routes])
 
   if (isLoading || loadingRoutes) {
     return (
@@ -80,19 +261,29 @@ export function RunEncounters() {
     encounterByRoute.set(enc.routeId, enc)
   }
 
-  const allRoutes = routes ?? []
-  const completedCount = allRoutes.filter((r) =>
-    encounterByRoute.has(r.id),
-  ).length
+  // Count completed locations (groups count as 1, standalone routes count as 1)
+  const completedCount = organizedRoutes.filter((r) => {
+    if (r.children.length > 0) {
+      // It's a group - check if any child has an encounter
+      return getGroupEncounter(r, encounterByRoute) !== null
+    }
+    // Standalone route
+    return encounterByRoute.has(r.id)
+  }).length
 
-  // Filter routes
-  const filteredRoutes =
-    filter === 'all'
-      ? allRoutes
-      : allRoutes.filter((r) => {
-          const enc = encounterByRoute.get(r.id)
-          return getRouteStatus(enc) === filter
-        })
+  const totalLocations = organizedRoutes.length
+
+  const toggleGroup = (groupId: number) => {
+    setExpandedGroups((prev) => {
+      const next = new Set(prev)
+      if (next.has(groupId)) {
+        next.delete(groupId)
+      } else {
+        next.add(groupId)
+      }
+      return next
+    })
+  }
 
   const handleRouteClick = (route: Route) => {
     const existing = encounterByRoute.get(route.id)
@@ -136,6 +327,21 @@ export function RunEncounters() {
     })
   }
 
+  // Filter routes
+  const filteredRoutes = organizedRoutes.filter((r) => {
+    if (filter === 'all') return true
+
+    if (r.children.length > 0) {
+      // It's a group
+      const groupEnc = getGroupEncounter(r, encounterByRoute)
+      return getRouteStatus(groupEnc ?? undefined) === filter
+    }
+
+    // Standalone route
+    const enc = encounterByRoute.get(r.id)
+    return getRouteStatus(enc) === filter
+  })
+
   return (
     <div className="max-w-4xl mx-auto p-8">
       {/* Header */}
@@ -150,7 +356,7 @@ export function RunEncounters() {
           Encounters
         </h1>
         <p className="text-gray-600 dark:text-gray-400 mt-1">
-          {run.game.name} &middot; {completedCount} / {allRoutes.length} routes
+          {run.game.name} &middot; {completedCount} / {totalLocations} locations
         </p>
       </div>
 
@@ -160,7 +366,7 @@ export function RunEncounters() {
           <div
             className="h-full bg-blue-500 rounded-full transition-all"
             style={{
-              width: `${allRoutes.length > 0 ? (completedCount / allRoutes.length) * 100 : 0}%`,
+              width: `${totalLocations > 0 ? (completedCount / totalLocations) * 100 : 0}%`,
             }}
           />
         </div>
@@ -199,6 +405,22 @@ 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}
+              />
+            )
+          }
+
+          // Standalone route (no children)
           const encounter = encounterByRoute.get(route.id)
           const rs = getRouteStatus(encounter)
           const si = statusIndicator[rs]

frontend/src/types/game.ts

@@ -13,6 +13,11 @@ export interface Route {
   name: string
   gameId: number
   order: number
+  parentRouteId: number | null
+}
+
+export interface RouteWithChildren extends Route {
+  children: Route[]
 }
 
 export interface Pokemon {