Dune/docs/ADVANCED_PREVIEW.md

Advanced preview

The user explicitly authorized a clearly labeled unfinished Advanced mode on 21 September 2026. This changes access to the existing development game, not the rules-completion or publication criteria.

Select and start

1. On the home page, choose Rules → Advanced preview, then Create a room.
2. Invite players or add AI seats. The preview supports two through six of the six classic factions: Atreides, Harkonnen, Fremen, Emperor, Guild and Bene Gesserit.
3. Optionally enable Tech Tokens with at least three players, or Stronghold Cards in the lobby.
4. Each human chooses Ready for Advanced preview. The host chooses Begin Advanced preview.

The host can also change Rules in an existing base-game lobby. Changing modes clears human readiness; native AI seats remain ready. Switching to Basic removes unused Stronghold Cards and keeps Tech Tokens. Rules cannot change after setup starts. Selecting Advanced on the home page clears expansion selections, which are outside this preview. Joining a room uses that room's existing rules.

The warning remains visible throughout Advanced play, including older Advanced development saves. Games use the existing room save, reconnect and private seat system. Basic remains the default.

Admission and saved behavior

Normal room creation already stores advanced: boolean; the same request format and exact tab retry are retained. The host-only lobby action {type: 'rules', advanced: boolean} changes the mode. The ordinary start action must contain advancedPreview: true for Advanced; a bare start remains rejected. Only a successful explicit start writes Game.advancedPreview: true. GameView.advancedPreview projects the marker as a boolean.

Start calls the genuine shared setup pipeline, including prediction, Traitors, starting forces, advisors, elites and the starting Treachery deal at their normal stages. The live API never dispatches a test/audit initializer. Fresh-lobby and unused-module checks prevent accidental redealing. Restored preview markers must still match their supported mode and roster. Mode changes, starts and ordinary continuation retain the existing version/CAS fence and private views.

Expansion factions/decks, Homeworlds, Nexus, Discoveries, Leader Skills, the Ecaz Treachery variant and separate audit profiles remain rejected by normal starts. Enabling Advanced cannot bypass those gates. For compatibility with exact older create retries, the create API still accepts the pre-existing expansion lobby format; those unsupported lobbies cannot start and have no expansion-removal control yet. The preview creation UI prevents that combination. No pending ruling is resolved by this access change; see the decision index.

Evidence and limits

• advanced-preview.test.ts: normal explicit starts, strict authority/admission, readiness, Basic fallback, genuine setup for all 57 base rosters with each of four existing legal AI profiles, card/force custody, JSON and private views.
• advanced-preview-controls.test.ts: visible mode/warning/host controls and exact Advanced create-request restoration.
• advanced-preview-recovery.test.ts: production room SQL, fresh module reload, both private seats, unchanged rejected requests and start/rules CAS races.
• advanced-preview-http.test.ts: normal authenticated endpoints, explicit opt-in, origin/authority checks, readiness, duplicate start and refresh.

An Advanced six-seat sample exposed an Intrusion save boundary: a shipment without an accompanying-advisor offer stored followup: undefined, which JSON removed and changed the restored private views. Ordinary and Junction shipment calls now omit that field when no follow-up exists. Focused regressions cover both routes and every seat across JSON restoration. The same genuine six-seat seed then completed at turn 10 after 1,531 actions and 41 restores. A separate ten-game Basic/Advanced base-roster matrix (two through six seats) completed with no rejected actions; these samples do not certify all Advanced interactions.

The private checkpoint directory records final check/build/HTTP results, ordinary preview-start complete-game samples, browser checks and saved-game preservation. These are development samples, not AI calibration or complete interaction coverage. Advanced base powers and timing audits remain unfinished, including the recorded Guild/special-Karama boundaries and advisor interactions. Stronghold Cards and Tech Tokens retain their existing implementation limits. Full visual acceptance, complete rules compliance and publication remain open.