diff --git a/.beans/nuzlocke-tracker-jq50--add-ability-to-end-a-run-successfailure.md b/.beans/nuzlocke-tracker-jq50--add-ability-to-end-a-run-successfailure.md
index f6c98aa..a4ee345 100644
--- a/.beans/nuzlocke-tracker-jq50--add-ability-to-end-a-run-successfailure.md
+++ b/.beans/nuzlocke-tracker-jq50--add-ability-to-end-a-run-successfailure.md
@@ -1,11 +1,11 @@
 ---
 # nuzlocke-tracker-jq50
 title: Add ability to end a run (success/failure)
-status: todo
+status: completed
 type: task
 priority: normal
 created_at: 2026-02-06T10:22:00Z
-updated_at: 2026-02-06T10:22:34Z
+updated_at: 2026-02-07T12:12:42Z
 parent: nuzlocke-tracker-f5ob
 ---
 
diff --git a/backend/src/app/api/runs.py b/backend/src/app/api/runs.py
index fb78ec6..1053149 100644
--- a/backend/src/app/api/runs.py
+++ b/backend/src/app/api/runs.py
@@ -1,3 +1,5 @@
+from datetime import datetime, timezone
+
 from fastapi import APIRouter, Depends, HTTPException, Response
 from sqlalchemy import select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -73,6 +75,15 @@ async def update_run(
         raise HTTPException(status_code=404, detail="Run not found")
 
     update_data = data.model_dump(exclude_unset=True)
+
+    # Auto-set completed_at when ending a run
+    if "status" in update_data and update_data["status"] in ("completed", "failed"):
+        if run.status != "active":
+            raise HTTPException(
+                status_code=400, detail="Only active runs can be ended"
+            )
+        update_data["completed_at"] = datetime.now(timezone.utc)
+
     for field, value in update_data.items():
         setattr(run, field, value)
 
diff --git a/frontend/src/components/EndRunModal.tsx b/frontend/src/components/EndRunModal.tsx
new file mode 100644
index 0000000..e14962c
--- /dev/null
+++ b/frontend/src/components/EndRunModal.tsx
@@ -0,0 +1,52 @@
+import type { RunStatus } from '../types'
+
+interface EndRunModalProps {
+  onConfirm: (status: RunStatus) => void
+  onClose: () => void
+  isPending?: boolean
+}
+
+export function EndRunModal({ onConfirm, onClose, isPending }: EndRunModalProps) {
+  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">End Run</h2>
+        </div>
+        <div className="px-6 py-6">
+          <p className="text-gray-600 dark:text-gray-400 mb-6">
+            How did your run end?
+          </p>
+          <div className="flex flex-col gap-3">
+            <button
+              onClick={() => onConfirm('completed')}
+              disabled={isPending}
+              className="w-full px-4 py-3 rounded-lg font-medium text-left border-2 border-blue-200 dark:border-blue-800 bg-blue-50 dark:bg-blue-900/20 text-blue-700 dark:text-blue-300 hover:border-blue-400 dark:hover:border-blue-600 disabled:opacity-50 transition-colors"
+            >
+              <div className="font-semibold">Victory</div>
+              <div className="text-sm opacity-80">Beat the game successfully</div>
+            </button>
+            <button
+              onClick={() => onConfirm('failed')}
+              disabled={isPending}
+              className="w-full px-4 py-3 rounded-lg font-medium text-left border-2 border-red-200 dark:border-red-800 bg-red-50 dark:bg-red-900/20 text-red-700 dark:text-red-300 hover:border-red-400 dark:hover:border-red-600 disabled:opacity-50 transition-colors"
+            >
+              <div className="font-semibold">Defeat</div>
+              <div className="text-sm opacity-80">All Pokemon fainted or gave up</div>
+            </button>
+          </div>
+        </div>
+        <div className="px-6 py-4 border-t border-gray-200 dark:border-gray-700 flex justify-end">
+          <button
+            onClick={onClose}
+            disabled={isPending}
+            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>
+        </div>
+      </div>
+    </div>
+  )
+}
diff --git a/frontend/src/components/index.ts b/frontend/src/components/index.ts
index 4675471..942e0e8 100644
--- a/frontend/src/components/index.ts
+++ b/frontend/src/components/index.ts
@@ -1,4 +1,5 @@
 export { EncounterModal } from './EncounterModal'
+export { EndRunModal } from './EndRunModal'
 export { GameCard } from './GameCard'
 export { GameGrid } from './GameGrid'
 export { Layout } from './Layout'
diff --git a/frontend/src/hooks/useRuns.ts b/frontend/src/hooks/useRuns.ts
index fbaa1d1..68fb31e 100644
--- a/frontend/src/hooks/useRuns.ts
+++ b/frontend/src/hooks/useRuns.ts
@@ -1,4 +1,5 @@
 import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query'
+import { toast } from 'sonner'
 import { getRuns, getRun, createRun, updateRun, deleteRun } from '../api/runs'
 import type { CreateRunInput, UpdateRunInput } from '../types/game'
 
@@ -30,9 +31,14 @@ export function useUpdateRun(id: number) {
   const queryClient = useQueryClient()
   return useMutation({
     mutationFn: (data: UpdateRunInput) => updateRun(id, data),
-    onSuccess: () => {
+    onSuccess: (_result, data) => {
       queryClient.invalidateQueries({ queryKey: ['runs'] })
+      queryClient.invalidateQueries({ queryKey: ['runs', id] })
+      if (data.status === 'completed') toast.success('Run marked as completed!')
+      else if (data.status === 'failed') toast.success('Run marked as failed')
+      else toast.success('Run updated')
     },
+    onError: (err) => toast.error(`Failed to update run: ${err.message}`),
   })
 }
 
diff --git a/frontend/src/pages/RunDashboard.tsx b/frontend/src/pages/RunDashboard.tsx
index d453c81..c8c0de6 100644
--- a/frontend/src/pages/RunDashboard.tsx
+++ b/frontend/src/pages/RunDashboard.tsx
@@ -1,9 +1,9 @@
 import { useState } from 'react'
 import { useParams, Link } from 'react-router-dom'
-import { useRun } from '../hooks/useRuns'
+import { useRun, useUpdateRun } from '../hooks/useRuns'
 import { useGameRoutes } from '../hooks/useGames'
 import { useUpdateEncounter } from '../hooks/useEncounters'
-import { StatCard, PokemonCard, RuleBadges, StatusChangeModal } from '../components'
+import { StatCard, PokemonCard, RuleBadges, StatusChangeModal, EndRunModal } from '../components'
 import type { RunStatus, EncounterDetail } from '../types'
 
 const statusStyles: Record<RunStatus, string> = {
@@ -13,14 +13,24 @@ const statusStyles: Record<RunStatus, string> = {
   failed: 'bg-red-100 text-red-800 dark:bg-red-900/40 dark:text-red-300',
 }
 
+function formatDuration(start: string, end: string) {
+  const ms = new Date(end).getTime() - new Date(start).getTime()
+  const days = Math.floor(ms / (1000 * 60 * 60 * 24))
+  if (days === 0) return 'Less than a day'
+  if (days === 1) return '1 day'
+  return `${days} days`
+}
+
 export function RunDashboard() {
   const { runId } = useParams<{ runId: string }>()
   const runIdNum = Number(runId)
   const { data: run, isLoading, error } = useRun(runIdNum)
   const { data: routes } = useGameRoutes(run?.gameId ?? null)
   const updateEncounter = useUpdateEncounter(runIdNum)
+  const updateRun = useUpdateRun(runIdNum)
   const [selectedEncounter, setSelectedEncounter] =
     useState<EncounterDetail | null>(null)
+  const [showEndRun, setShowEndRun] = useState(false)
 
   if (isLoading) {
     return (
@@ -46,6 +56,7 @@ export function RunDashboard() {
     )
   }
 
+  const isActive = run.status === 'active'
   const alive = run.encounters.filter(
     (e) => e.status === 'caught' && e.faintLevel === null,
   )
@@ -87,6 +98,52 @@ export function RunDashboard() {
         </div>
       </div>
 
+      {/* Completion Banner */}
+      {!isActive && (
+        <div
+          className={`rounded-lg p-4 mb-6 ${
+            run.status === 'completed'
+              ? 'bg-blue-50 dark:bg-blue-900/20 border border-blue-200 dark:border-blue-800'
+              : 'bg-red-50 dark:bg-red-900/20 border border-red-200 dark:border-red-800'
+          }`}
+        >
+          <div className="flex items-center gap-3">
+            <span className="text-2xl">{run.status === 'completed' ? '\u{1f3c6}' : '\u{1faa6}'}</span>
+            <div>
+              <p
+                className={`font-semibold ${
+                  run.status === 'completed'
+                    ? 'text-blue-800 dark:text-blue-200'
+                    : 'text-red-800 dark:text-red-200'
+                }`}
+              >
+                {run.status === 'completed' ? 'Victory!' : 'Defeat'}
+              </p>
+              <p
+                className={`text-sm ${
+                  run.status === 'completed'
+                    ? 'text-blue-600 dark:text-blue-400'
+                    : 'text-red-600 dark:text-red-400'
+                }`}
+              >
+                {run.completedAt && (
+                  <>
+                    Ended{' '}
+                    {new Date(run.completedAt).toLocaleDateString(undefined, {
+                      year: 'numeric',
+                      month: 'short',
+                      day: 'numeric',
+                    })}
+                    {' \u00b7 '}
+                    Duration: {formatDuration(run.startedAt, run.completedAt)}
+                  </>
+                )}
+              </p>
+            </div>
+          </div>
+        </div>
+      )}
+
       {/* Stats */}
       <div className="grid grid-cols-2 md:grid-cols-4 gap-3 mb-6">
         <StatCard
@@ -115,7 +172,7 @@ export function RunDashboard() {
       {/* Active Team */}
       <div className="mb-6">
         <h2 className="text-lg font-semibold text-gray-900 dark:text-gray-100 mb-3">
-          Active Team
+          {isActive ? 'Active Team' : 'Final Team'}
         </h2>
         {alive.length === 0 ? (
           <p className="text-gray-500 dark:text-gray-400 text-sm">
@@ -127,7 +184,7 @@ export function RunDashboard() {
               <PokemonCard
                 key={enc.id}
                 encounter={enc}
-                onClick={() => setSelectedEncounter(enc)}
+                onClick={isActive ? () => setSelectedEncounter(enc) : undefined}
               />
             ))}
           </div>
@@ -146,7 +203,7 @@ export function RunDashboard() {
                 key={enc.id}
                 encounter={enc}
                 showFaintLevel
-                onClick={() => setSelectedEncounter(enc)}
+                onClick={isActive ? () => setSelectedEncounter(enc) : undefined}
               />
             ))}
           </div>
@@ -154,13 +211,23 @@ export function RunDashboard() {
       )}
 
       {/* Quick Actions */}
-      <div className="mt-8">
-        <Link
-          to={`/runs/${runId}/encounters`}
-          className="px-4 py-2 bg-blue-600 text-white rounded-lg font-medium hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 transition-colors"
-        >
-          Log Encounter
-        </Link>
+      <div className="mt-8 flex gap-3">
+        {isActive && (
+          <>
+            <Link
+              to={`/runs/${runId}/encounters`}
+              className="px-4 py-2 bg-blue-600 text-white rounded-lg font-medium hover:bg-blue-700 focus:outline-none focus:ring-2 focus:ring-blue-500 focus:ring-offset-2 transition-colors"
+            >
+              Log Encounter
+            </Link>
+            <button
+              onClick={() => setShowEndRun(true)}
+              className="px-4 py-2 border border-gray-300 dark:border-gray-600 rounded-lg font-medium hover:bg-gray-50 dark:hover:bg-gray-700 focus:outline-none focus:ring-2 focus:ring-gray-400 focus:ring-offset-2 transition-colors"
+            >
+              End Run
+            </button>
+          </>
+        )}
       </div>
 
       {/* Status Change Modal */}
@@ -176,6 +243,20 @@ export function RunDashboard() {
           isPending={updateEncounter.isPending}
         />
       )}
+
+      {/* End Run Modal */}
+      {showEndRun && (
+        <EndRunModal
+          onConfirm={(status) => {
+            updateRun.mutate(
+              { status },
+              { onSuccess: () => setShowEndRun(false) },
+            )
+          }}
+          onClose={() => setShowEndRun(false)}
+          isPending={updateRun.isPending}
+        />
+      )}
     </div>
   )
 }