diff --git a/app/page.tsx b/app/page.tsx
index f0d50948..472f5cbc 100644
--- a/app/page.tsx
+++ b/app/page.tsx
@@ -1085,10 +1085,7 @@ export default function Home() {
             disabled={busy || claimUncertain}
             onChange={(value) => {
               setAdvanced(value);
-              if (value) {
-                setExpansions([]);
-                if (f.expansion !== 'base') setSelected('atreides');
-              }
+              if (value && f.expansion !== 'base' && !expansions.includes(f.expansion)) setSelected('atreides');
             }}
           />
           <p className="fine">2–6 players · up to 10 turns</p>
@@ -1101,7 +1098,7 @@ export default function Home() {
               <label className="expansion" key={x.id}>
                 <input
                   type="checkbox"
-                  disabled={busy || claimUncertain || advanced}
+                  disabled={busy || claimUncertain}
                   checked={expansions.includes(x.id)}
                   onChange={(e) => {
                     setExpansions(
diff --git a/components/game-table.tsx b/components/game-table.tsx
index 1b55a19b..d0bbf242 100644
--- a/components/game-table.tsx
+++ b/components/game-table.tsx
@@ -2060,8 +2060,8 @@ export function GameTable({
                     !g.players.every((p) => p.ready),
                 )}
               <p className="development-note">
-                Playable core under development. Advanced is available as an
-                unfinished preview. Expansion games are not yet available.
+                Playable core under development. Advanced and expansion factions
+                are unfinished previews; some interactions may still need fixes.
               </p>
             </>
           ) : g.status === 'setup' && !g.decision ? (
diff --git a/docs/CURRENT_STATUS.md b/docs/CURRENT_STATUS.md
index fe5ed34c..9e1ec3a5 100644
--- a/docs/CURRENT_STATUS.md
+++ b/docs/CURRENT_STATUS.md
@@ -29,6 +29,18 @@ optional skill bands, combinations and public expansion starts remain open.
 Rules implementation continues; comprehensive assurance and administration
 remain deferred until all rules are implemented.
 
+**Expansion-faction lobby starts open — 17 October (user-directed speed pass).**
+Hosts may now start Basic or Advanced-preview games with Ix, CHOAM and/or Ecaz
+factions from the normal lobby; the start routes through the existing native
+faction setup. Optional Tech Tokens follow the native profile; Stronghold Cards,
+Homeworlds, Nexus, Discovery, Skills and independent cards keep their dev entries.
+Eight all-AI 10-turn games (Basic/Advanced × Ix, CHOAM, Ecaz, all-three six-seat)
+finished with no stuck or rejected actions. The lobby note warns of unfinished
+interactions. **Known regression (fix later):** the full suite shows133/9868
+failures, mostly Nexus inspection/Cunning/Sardaukar and Bureaucrat suites; they
+began between `bc09ac3` (14 Oct, passing) and `82f1aae` (15 Oct) and predate
+this change. Not yet triaged.
+
 **Independent36/all14 Skills composition — 17 October.** Fresh ready classic
 Basic/Advanced all14 now admits the printed independent three-card variant
 (original36, no other modules, no played-game conversion). Real Recruits after a
diff --git a/game/engine.ts b/game/engine.ts
index 7f8a47cc..bbf323bd 100644
--- a/game/engine.ts
+++ b/game/engine.ts
@@ -8404,9 +8404,12 @@ function baseStartProfileBlock(g: Game): string | null {
   if (g.ecazTreachery) return 'Ecaz Treachery Cards are still being implemented.';
   if (g.moritaniAssassinatePreview || g.moritaniAssassinate)
     return 'Separate development profiles cannot be enabled by a normal start.';
-  if (!g.players.every(p => FACTIONS.some(entry => entry.id === p.faction && entry.expansion === 'base')))
-    return 'Expansion factions are still being implemented.';
-  if (g.expansions.length !== 0) return 'Expansion rules are still being implemented.';
+  const expansionFactions = g.expansions.length > 0 ||
+    !g.players.every(p => FACTIONS.some(entry => entry.id === p.faction && entry.expansion === 'base'));
+  if (expansionFactions && g.strongholdCards)
+    return 'Stronghold Cards with expansion factions still use a development profile.';
+  if (expansionFactions && g.techTokens && !nativeFactionTechProfile(g))
+    return 'Tech Tokens with expansion factions need a supported three-through-six-seat native roster.';
   return null;
 }
 function advancedPreviewIntegrity(g: Game) {
@@ -8465,7 +8468,7 @@ function requireFreshBaseRuntime(g: Game) {
     JSON.stringify(g[key]) === JSON.stringify(fresh[key])),
   'Starting a base table cannot retain existing game resources, histories or continuations.');
 }
-function start(g: Game, advancedPreview = false) {
+function start(g: Game, advancedPreview = false): Game {
   requireRule(g.players.length >= 2, 'At least two players are needed.');
   requireRule(
     g.players.every((p) => p.ready),
@@ -8476,6 +8479,12 @@ function start(g: Game, advancedPreview = false) {
   requireRule(!advancedPreview || g.advanced, 'Choose Advanced preview rules before starting that preview.');
   const blocked = baseStartProfileBlock(g);
   requireRule(!blocked, blocked ?? 'This rules profile is unavailable.');
+  if (g.expansions.length) {
+    // Expansion factions use the genuine native faction setup (elites, decks, cache).
+    const initialized = initializeFactionExpansionsGameForAudit(g);
+    if (advancedPreview) initialized.advancedPreview = true;
+    return initialized;
+  }
   requireFreshSetup(g);
   requireRule(!g.techTokens || JSON.stringify(g.techTokens) === JSON.stringify(createTechTokens()),
     'Start with unused Tech Tokens before assigning their initial owners.');
@@ -8484,6 +8493,7 @@ function start(g: Game, advancedPreview = false) {
   requireFreshBaseRuntime(g);
   initializeSetup(g);
   if (advancedPreview) g.advancedPreview = true;
+  return g;
 }
 function skillRule<T>(operation: () => T): T {
   try {
@@ -32324,8 +32334,7 @@ function applyActionInner(
       requireRule(Object.keys(action).every(key => key === 'type' || key === 'advancedPreview') &&
         (action.advancedPreview === undefined || action.advancedPreview === true),
       'Start this table, or explicitly choose Advanced preview.');
-      start(g, action.advancedPreview === true);
-      return g;
+      return start(g, action.advancedPreview === true);
     }
     if (t === 'faction') {
       const f = action.faction as FactionId;
diff --git a/game/leader-skill-profile.ts b/game/leader-skill-profile.ts
index 18bc8365..02c8dd16 100644
--- a/game/leader-skill-profile.ts
+++ b/game/leader-skill-profile.ts
@@ -532,7 +532,8 @@ export function classicIndependentLeaderSkillsProfile(game: LeaderSkillProfile):
 /** Shared by rule quotes, controls and minimal legal bot participation. */
 export function ordinaryLeaderSkillModeSupported(game: LeaderSkillProfile): boolean {
   return classicIndependentLeaderSkillsProfile(game) || (noOtherLeaderSkillModules(game) &&
-    (!game.expansions.length || nativeExpansionLeaderSkillsProfile(game))) ||
+    (!game.expansions.length || nativeExpansionLeaderSkillsProfile(game) ||
+      (game.expansions.length === 1 && game.expansions[0] === 'choam'))) ||
     classicTechLeaderSkillsProfile(game) || nativeTechLeaderSkillsProfile(game) ||
     strongholdLeaderSkillsProfile(game) || classicNexusLeaderSkillsProfile(game) ||
     guildBetrayalNexusLeaderSkillsProfile(game) ||
diff --git a/tests/choam-auditor-lifecycle.test.ts b/tests/choam-auditor-lifecycle.test.ts
index 254843f1..380b9127 100644
--- a/tests/choam-auditor-lifecycle.test.ts
+++ b/tests/choam-auditor-lifecycle.test.ts
@@ -11,7 +11,6 @@ import {
   newPlayer,
   joinGame,
   viewGame,
-  initializeBaseGameForAudit,
   type Game,
 } from '../game/engine';
 import { baseDeck, createAuditorLeader, CHOAM_AUDITOR_ID } from '../game/cards';
@@ -97,7 +96,7 @@ function setupModule() {
   return exports.initializeSetup!;
 }
 
-void test('real isolated initializer adds the Advanced Auditor before prediction and traitor dealing; public gates stay closed', () => {
+void test('real isolated initializer adds the Advanced Auditor before prediction and traitor dealing', () => {
   const initialize = setupModule();
   for (const advanced of [false, true]) {
     let g = createGame(
@@ -107,18 +106,6 @@ void test('real isolated initializer adds the Advanced Auditor before prediction
     );
     joinGame(g, newPlayer('b', 'Bene Gesserit', 'beneGesserit'));
     for (const id of ['c', 'b']) g = applyAction(g, id, { type: 'ready' });
-    const before = structuredClone(g);
-    assert.throws(
-      () => applyAction(g, 'c', { type: 'start' }),
-      advanced ? /Advanced preview/ : /still being implemented/,
-    );
-    if (advanced)
-      assert.throws(
-        () => applyAction(g, 'c', { type: 'start', advancedPreview: true }),
-        /Expansion factions are still being implemented/,
-      );
-    assert.throws(() => initializeBaseGameForAudit(g), /base factions/);
-    assert.deepEqual(g, before);
     initialize(g);
     assert.equal(g.setupStage, 'prediction');
     assert.equal(
diff --git a/tests/ix-prototype.test.ts b/tests/ix-prototype.test.ts
index 27f0b2a5..b2b4ca8c 100644
--- a/tests/ix-prototype.test.ts
+++ b/tests/ix-prototype.test.ts
@@ -299,18 +299,7 @@ for (const [advanced, seed] of [
       );
     }));
 
-void test('the Ix prototype keeps public gates and rejects unsupported or nonempty lobbies without mutation', () => {
-  const publicLobby = lobby(false, [
-    ['a', 'atreides'],
-    ['h', 'harkonnen'],
-  ]);
-  const publicBefore = structuredClone(publicLobby);
-  assert.throws(
-    () => applyAction(publicLobby, publicLobby.host, { type: 'start' }),
-    /Expansion rules are still being implemented/,
-  );
-  assert.deepEqual(publicLobby, publicBefore);
-
+void test('the Ix prototype rejects unsupported or nonempty lobbies without mutation', () => {
   const absent = createGame('NOIXPROTO', newPlayer('a', 'a', 'atreides'));
   absent.players.push(newPlayer('h', 'h', 'harkonnen'));
   absent.players.forEach((p) => (p.ready = true));
diff --git a/tests/richese-engine.test.ts b/tests/richese-engine.test.ts
index 109344e3..4248f233 100644
--- a/tests/richese-engine.test.ts
+++ b/tests/richese-engine.test.ts
@@ -272,7 +272,7 @@ void test('Atreides inspection grants only its entitled view and survives JSON b
   assert.equal(viewGame(g, 'e').richeseAuction!.cardId, null);
   assert.equal(g.players[0].hand[0].id, card.id);
 });
-void test('connected cache-cancel restores the ordinary pool while seller self-bid and lobby gates still reject atomically', () => {
+void test('connected cache-cancel restores the ordinary pool while seller self-bid rejects atomically', () => {
   const before = fixture();
   const k = before.deck.find((c) => c.effect === 'karama')!;
   before.players[2].hand = [k];
@@ -295,13 +295,6 @@ void test('connected cache-cancel restores the ordinary pool while seller self-b
   const exact = structuredClone(g);
   assert.throws(() => bid(g, 'r', 1), /self-bid/);
   assert.deepEqual(g, exact);
-  const lobby = createGame('RICHESE1', newPlayer('r', 'Richese', 'richese'));
-  lobby.players.push(newPlayer('e', 'Emperor', 'emperor'));
-  lobby.players.forEach((p) => (p.ready = true));
-  assert.throws(
-    () => applyAction(lobby, 'r', { type: 'start' }),
-    /still being implemented/,
-  );
 });
 
 void test('an outbid ally-funded player whose hand fills is automatically skipped without reserving losing credit', () => {