diff --git a/.gitea/workflows/ci.yaml b/.gitea/workflows/ci.yaml
index 5e58272..f8ac898 100644
--- a/.gitea/workflows/ci.yaml
+++ b/.gitea/workflows/ci.yaml
@@ -214,9 +214,21 @@ jobs:
         run: pnpm exec playwright install chromium webkit
         timeout-minutes: 5
 
+      # The offline e2e plays a real local vs_ai game, so it needs the per-variant dawgs; fetch the
+      # release the same way the Go jobs do and point the mock preview's copy step (scripts/
+      # e2e-dict.mjs, via E2E_DICT_DIR below) at it.
+      - name: Fetch dictionary DAWGs
+        run: |
+          mkdir -p "${GITHUB_WORKSPACE}/dawg"
+          curl -fsSL -o /tmp/dawg.tar.gz "https://gitea.iliadenisov.ru/developer/scrabble-dictionary/releases/download/${DICT_VERSION}/scrabble-dawg-${DICT_VERSION}.tar.gz"
+          tar xzf /tmp/dawg.tar.gz -C "${GITHUB_WORKSPACE}/dawg"
+          ls -la "${GITHUB_WORKSPACE}/dawg"
+
       - name: E2E smoke (mock)
         run: pnpm run test:e2e
         timeout-minutes: 5
+        env:
+          E2E_DICT_DIR: ${{ github.workspace }}/dawg
 
   # conformance proves the client's local move preview (the ported dawg reader +
   # validator, ui/src/lib/dict) byte-for-byte against the authoritative Go engine:
diff --git a/docs/TESTING.md b/docs/TESTING.md
index e22de9c..14c0eca 100644
--- a/docs/TESTING.md
+++ b/docs/TESTING.md
@@ -20,7 +20,18 @@ tests or touching CI.
   derivation and the GCG share/copy/download choice, plus Playwright specs against the
   mock for the friends screen (code issue/redeem, accept a request), the lobby
   invitations section, the stats screen, profile editing, and the export chooser's
-  finished-only visibility + its signed-URL download flow (route-intercepted).
+  finished-only visibility + its signed-URL download flow (route-intercepted). The
+  **offline mode** spec (`e2e/offline.spec.ts`) plays a full device-local `vs_ai` game
+  end-to-end: it forces the installed-PWA display mode, enters offline through the
+  Settings toggle (whose readiness check fetches the enabled variants' dawgs), then creates
+  and plays a local game with a **pinned bag seed** (`window.__mock.setLocalSeed`, so the
+  rack is deterministic and the human can tap out a precomputed opening), asserting the
+  robot's real reply and the IndexedDB replay after a reload. A local game needs a real
+  dictionary, so the mock's `fetchDict` serves the per-variant dawgs from the preview
+  build's `/e2edict/`, copied in by `scripts/e2e-dict.mjs` from `E2E_DICT_DIR` — the `ui`
+  CI job fetches the `scrabble-dictionary` release like the Go jobs; locally it defaults to
+  the sibling `scrabble-solver/dawg`. These dawgs are never committed and never enter the
+  production build.
 - **Render sidecar** — `renderer/` (Node + skia-canvas executing the shared
   `ui/src/lib/gameimage.ts`) carries a `node --test` smoke: the committed fixture (a
   real self-played 35-move game) must rasterize to a plausible PNG
diff --git a/ui/e2e/offline.spec.ts b/ui/e2e/offline.spec.ts
new file mode 100644
index 0000000..cc42f6e
--- /dev/null
+++ b/ui/e2e/offline.spec.ts
@@ -0,0 +1,83 @@
+import { test, expect, type Page } from './fixtures';
+
+// The offline mode is gated to an installed standalone PWA with a confirmed email. The mock account
+// has an email; force the standalone display mode so the Settings offline toggle is offered. Only the
+// `(display-mode: standalone)` query is overridden — theme/reduce-motion queries pass through.
+async function forceStandalone(page: Page): Promise<void> {
+  await page.addInitScript(() => {
+    const orig = window.matchMedia.bind(window);
+    window.matchMedia = (q: string) =>
+      (q.includes('display-mode: standalone')
+        ? { matches: true, media: q, onchange: null, addEventListener() {}, removeEventListener() {}, addListener() {}, removeListener() {}, dispatchEvent: () => false }
+        : orig(q)) as MediaQueryList;
+  });
+}
+
+// After a load or reload, land in the lobby (dismiss the login screen if it is shown).
+async function enterLobby(page: Page): Promise<void> {
+  const guest = page.getByRole('button', { name: /guest|гост/i });
+  if (await guest.count()) await guest.first().click();
+  // The lobby tab bar has three tabs in a fixed order: New (0), Stats (1), Settings (2). nth() is
+  // robust to locale, emoji variation selectors and the coachmark anchors (which the first-run
+  // onboarding strips after it completes).
+  await expect(page.locator('button.tab').nth(2)).toBeVisible();
+}
+
+// Pick a rack tile by its glyph and drop it on a board square (the rack of the pinned-seed game has
+// all-distinct letters, so the glyph is unambiguous).
+async function placeTile(page: Page, glyph: string, row: number, col: number): Promise<void> {
+  await page.locator('.rack .tile', { hasText: glyph }).first().click();
+  await page.locator(`[data-cell][data-row="${row}"][data-col="${col}"]`).click();
+}
+
+test.describe('offline mode', () => {
+  test('enter via the toggle, play a local vs_ai game, persist across a reload', async ({ page }) => {
+    await forceStandalone(page);
+    await page.goto('/');
+    await enterLobby(page);
+
+    // Online: a seeded online game (vs Ann) is listed.
+    await expect(page.getByText('Ann', { exact: false }).first()).toBeVisible();
+
+    // Enter offline through the real Settings toggle (its readiness check fetches every enabled
+    // variant's dawg, served from /e2edict/ by the mock) — the header turns blue with the chip.
+    await page.locator('button.tab').nth(2).click();
+    await page.getByRole('button', { name: /^(Offline|Оффлайн)$/ }).click();
+    await expect(page.locator('header.nav.offline')).toBeVisible({ timeout: 15000 });
+
+    // Back in the (now offline) lobby: the online games are hidden and the Stats tab is disabled.
+    await page.getByRole('button', { name: /Back|Назад/i }).click();
+    await expect(page.locator('button.tab').nth(2)).toBeVisible();
+    await expect(page.getByText('Ann', { exact: false })).toHaveCount(0);
+    await expect(page.locator('button.tab').nth(1)).toBeDisabled();
+
+    // Create a device-local English vs_ai game with a pinned bag seed (deals the rack NEWYMAO).
+    await page.evaluate(() => (window as unknown as { __mock: { setLocalSeed(s: string): void } }).__mock.setLocalSeed('1'));
+    await page.locator('button.tab').nth(0).click();
+    // The English variant's display name is "Scrabble" (Latin) in both locales — the Russian
+    // variants are "Скрэббл"/"Эрудит"/"Erudite", so this uniquely selects the English game.
+    await page.locator('.variant', { hasText: 'Scrabble' }).click();
+    await page.locator('button.invite').click();
+    await expect(page.locator('[data-cell]').first()).toBeVisible();
+
+    // The human plays WAY horizontally across the centre (7,5)-(7,7).
+    await placeTile(page, 'W', 7, 5);
+    await placeTile(page, 'A', 7, 6);
+    await placeTile(page, 'Y', 7, 7);
+    await expect(page.locator('[data-cell].pending')).toHaveCount(3);
+    await page.locator('.make').click();
+
+    // The play commits and the local robot replies with a real move, so the board carries more than
+    // WAY's three tiles.
+    await expect(async () => {
+      expect(await page.locator('[data-cell].filled').count()).toBeGreaterThan(3);
+    }).toPass({ timeout: 15000 });
+    const filled = await page.locator('[data-cell].filled').count();
+
+    // Reload: the hash router restores the /game/<id> route and the local game replays from
+    // IndexedDB with every committed tile intact.
+    await page.reload();
+    await expect(page.locator('[data-cell]').first()).toBeVisible();
+    await expect(page.locator('[data-cell].filled')).toHaveCount(filled);
+  });
+});
diff --git a/ui/playwright.config.ts b/ui/playwright.config.ts
index b3d34cd..e993a88 100644
--- a/ui/playwright.config.ts
+++ b/ui/playwright.config.ts
@@ -21,8 +21,11 @@ export default defineConfig({
     // under /app/ and /telegram/): served from the preview root, an absolute base keeps assets at
     // /assets/ so the SPA-fallback also boots a subpath like /telegram/. Base only prefixes asset
     // URLs, so the minified JS under test is identical to the contour's.
+    // After the mock build, copy the real per-variant dawgs into the preview output (dist-e2e) so the
+    // offline spec can play a real local vs_ai game; the files are e2e-only (never committed, never in
+    // the production build). Source: E2E_DICT_DIR (CI: the fetched release; local: the sibling).
     command:
-      'pnpm exec vite build --mode mock --base / --outDir dist-e2e --emptyOutDir && pnpm exec vite preview --outDir dist-e2e --port 4173 --strictPort',
+      'pnpm exec vite build --mode mock --base / --outDir dist-e2e --emptyOutDir && node scripts/e2e-dict.mjs && pnpm exec vite preview --outDir dist-e2e --port 4173 --strictPort',
     url: 'http://localhost:4173',
     reuseExistingServer: !process.env.CI,
     timeout: 120_000,
diff --git a/ui/scripts/e2e-dict.mjs b/ui/scripts/e2e-dict.mjs
new file mode 100644
index 0000000..9c8ec20
--- /dev/null
+++ b/ui/scripts/e2e-dict.mjs
@@ -0,0 +1,35 @@
+// Copies the real per-variant dictionary DAWGs into the mock e2e preview output (dist-e2e/e2edict/)
+// so the offline spec can create and play a real local vs_ai game (the mock's fetchDict serves these
+// files — see lib/mock/client.ts). The dawgs are NEVER committed and never enter the production
+// build; they live only in the throwaway dist-e2e/ that `vite preview` serves for Playwright.
+//
+// Source directory: E2E_DICT_DIR — in CI the fetched scrabble-dictionary release
+// ($GITHUB_WORKSPACE/dawg); locally it defaults to the sibling scrabble-solver/dawg checkout. A
+// missing source only warns (so the other, dawg-free specs still run); the offline spec then fails
+// with an obvious HTTP 404 from fetchDict.
+
+import { existsSync, mkdirSync, copyFileSync } from 'node:fs';
+import { join } from 'node:path';
+
+const srcDir = process.env.E2E_DICT_DIR ?? '../../scrabble-solver/dawg';
+const outDir = 'dist-e2e/e2edict';
+
+// The app's Variant enum value -> the release dawg file name (matches the movegen/parity mapping).
+const dawgFor = {
+  scrabble_en: 'en_sowpods',
+  scrabble_ru: 'ru_scrabble',
+  erudit_ru: 'ru_erudit',
+};
+
+mkdirSync(outDir, { recursive: true });
+let copied = 0;
+for (const [variant, file] of Object.entries(dawgFor)) {
+  const src = join(srcDir, `${file}.dawg`);
+  if (!existsSync(src)) {
+    console.warn(`e2e-dict: missing ${src} — the offline spec will 404 (set E2E_DICT_DIR)`);
+    continue;
+  }
+  copyFileSync(src, join(outDir, `${variant}.dawg`));
+  copied++;
+}
+console.log(`e2e-dict: copied ${copied}/${Object.keys(dawgFor).length} dawgs from ${srcDir} -> ${outDir}`);
diff --git a/ui/src/lib/gateway.ts b/ui/src/lib/gateway.ts
index 02a9482..cfefa9c 100644
--- a/ui/src/lib/gateway.ts
+++ b/ui/src/lib/gateway.ts
@@ -5,6 +5,7 @@
 import type { GatewayClient } from './client';
 import { MockGateway } from './mock/client';
 import { createTransport } from './transport';
+import { setForcedSeed } from './localgame/id';
 import { reportOffline, reportOnline } from './connection.svelte';
 import { clearMaintenance, maintenanceRecovered, reportMaintenance } from './maintenance.svelte';
 
@@ -41,6 +42,7 @@ if (isMock && typeof window !== 'undefined') {
         setGameLimit(v: boolean): void;
         clearEmail(): void;
         confirmEmailOutOfBand(email: string): void;
+        setLocalSeed(seed: string): void;
       };
     }
   ).__mock = {
@@ -50,5 +52,8 @@ if (isMock && typeof window !== 'undefined') {
     setGameLimit: (v: boolean) => (gateway as MockGateway).setGameLimit(v),
     clearEmail: () => (gateway as MockGateway).mockClearEmail(),
     confirmEmailOutOfBand: (email: string) => (gateway as MockGateway).mockConfirmEmailOutOfBand(email),
+    // Pin the next local game's bag seed, so the offline e2e deals a known rack (a bigint as a
+    // string — window hooks marshal strings cleanly).
+    setLocalSeed: (seed: string) => setForcedSeed(BigInt(seed)),
   };
 }
diff --git a/ui/src/lib/localgame/id.ts b/ui/src/lib/localgame/id.ts
index bba13ef..e25fc86 100644
--- a/ui/src/lib/localgame/id.ts
+++ b/ui/src/lib/localgame/id.ts
@@ -17,7 +17,20 @@ export function newLocalGameId(): string {
   return `${LOCAL_ID_PREFIX}${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 10)}`;
 }
 
-/** randomSeed returns a random 32-bit seed for a new local game's deterministic bag. */
+// A test seam for the mock e2e: pinning the seed makes a local game deal a known rack, so a spec
+// can play a precomputed opening word. Only the mock build's window.__mock wires setForcedSeed
+// (see lib/gateway.ts); a production build never calls it, so randomSeed stays truly random.
+let forcedSeed: bigint | null = null;
+
+/** setForcedSeed pins the value randomSeed returns (the mock-e2e seam); pass null to restore
+ *  randomness. */
+export function setForcedSeed(seed: bigint | null): void {
+  forcedSeed = seed;
+}
+
+/** randomSeed returns a random 32-bit seed for a new local game's deterministic bag (or the pinned
+ *  seed when a test has set one via setForcedSeed). */
 export function randomSeed(): bigint {
+  if (forcedSeed !== null) return forcedSeed;
   return BigInt(Math.floor(Math.random() * 0xffffffff));
 }
diff --git a/ui/src/lib/mock/client.ts b/ui/src/lib/mock/client.ts
index a1219e2..6f6ebe9 100644
--- a/ui/src/lib/mock/client.ts
+++ b/ui/src/lib/mock/client.ts
@@ -166,9 +166,13 @@ export class MockGateway implements GatewayClient {
     // The mock never blocks; the blocked screen is driven directly via the mock-mode __block seam.
     return { blocked: false, permanent: false, until: '', reason: '' };
   }
-  async fetchDict(_variant: Variant, _version: string, _opts?: { signal?: AbortSignal; reload?: boolean }): Promise<ArrayBuffer> {
-    // No local dictionary in mock mode; the caller falls back to the mock evaluate.
-    throw new Error('fetchDict unsupported in mock');
+  async fetchDict(variant: Variant, _version: string, opts?: { signal?: AbortSignal; reload?: boolean }): Promise<ArrayBuffer> {
+    // The offline e2e serves the real per-variant dawgs from the preview build's /e2edict/ (copied
+    // in by scripts/e2e-dict.mjs from the scrabble-dictionary release, never committed), so a local
+    // vs_ai game can generate real moves. Version is ignored (a single served file per variant).
+    const res = await fetch(`/e2edict/${variant}.dawg`, { signal: opts?.signal });
+    if (!res.ok) throw new Error(`fetchDict ${variant}: HTTP ${res.status}`);
+    return res.arrayBuffer();
   }
 
   async reportLocalEval(_counts: Record<string, number>): Promise<void> {