v0.7.0 — four game types, a lobby you can read and leave, and a multiplayer game that makes a sound

The multiplayer set-up, the lobby, the start of a game, and four signals a remote client had never
been sent. Reasoning, the preset table and what was verified how: CHANGELOG.md.

- Co-op, Competitive, Cutthroat, Solitaire and Custom, on both screens, from one shared block —
  they had drifted, and each was missing a question the other asked.
- A player reads the whole rule set before taking a seat, may leave a lobby or a running game, and
  keeps a seat across a reload. The host may clear a chair. The browser remembers every game it is
  in, not just the last one.
- The start of a game is drawn: a handoff beat, an announcement, the code and type in the header.
- Sound, the timetable flash, announcements and the just-drawn badge now reach a remote client;
  justDrawn goes to the seat that drew it and nobody else.
- Played on StartOS, which found the rest: an Extra belongs to the player who played it, the board
  never named the Superintendent, bot seats were reported as absent players, and rule section
  numbers are out of every string a player reads.

Also carries the previous session's Heavy Grade documentation work — asked again, answer unchanged.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016JczK5i33ZNSf2PtzZqdhS

src/engine/advance.ts

@@ -266,8 +266,14 @@ function newTrainPhase(s: GameState, events: GameEvent[]): AdvanceResult {
    * chooser is the acting player; §7 says the player who PLAYED the card, which is the same person
    * in solitaire and needs `pendingExtras` to carry a player before it is not.
    */
-  if (s.pendingExtras.length > 0 && s.freeTrays.length > 0) {
-    s.clock.currentActor = actorAt(s, s.clock.actorOffset % s.players.length);
+  const extra = s.pendingExtras[0];
+  if (extra !== undefined && s.freeTrays.length > 0) {
+    // §7 — the player who PLAYED the card places it. `pendingExtras` carries them (2026-08-23);
+    // before that it was a bare train number and this asked whoever the acting order was on, which
+    // is the same person in solitaire and the wrong one at every table. Reported by Jesse from a
+    // two-player game.
+    if (s.clock.currentActor !== extra.player) events.push({ type: 'actorChanged', player: extra.player });
+    s.clock.currentActor = extra.player;
     return { events, needsInput: true };
   }
 
@@ -285,7 +291,16 @@ function newTrainPhase(s: GameState, events: GameEvent[]): AdvanceResult {
   const filling = trainNeedingCars(s);
   if (filling) {
     const tray = s.trays.get(filling)!;
-    const nextActor = actorAt(s, tray.consist.length % s.players.length);
+    /**
+     * TWO DIFFERENT RULES, and §7 states them a paragraph apart. A TIMETABLED train's consist is
+     * built by the table — "starting with the Superintendent and working left, each player may place
+     * ONE car" — while an EXTRA is loaded by the player who played it, "as he chooses". So an Extra
+     * does not enter the round at all; it belongs to `builtBy` until it is full.
+     */
+    const nextActor =
+      tray.trainIsExtra && tray.builtBy !== undefined
+        ? tray.builtBy
+        : actorAt(s, tray.consist.length % s.players.length);
     if (s.clock.currentActor !== nextActor) events.push({ type: 'actorChanged', player: nextActor });
     s.clock.currentActor = nextActor;
     return { events, needsInput: true };

src/engine/apply.ts

@@ -1050,7 +1050,11 @@ export function check(s: GameState, player: PlayerIndex, i: Intent): RejectionCo
     // -- New Train ------------------------------------------------------------
     case 'newTrain.startExtra': {
       if (!inPhase(s, 'newTrain')) return 'WRONG_PHASE';
-      if (!s.pendingExtras.includes(i.trainNumber)) return 'NO_EXTRA_PENDING';
+      const pending = s.pendingExtras.find((x) => x.trainNumber === i.trainNumber);
+      if (!pending) return 'NO_EXTRA_PENDING';
+      // §7 — "the player who played the card MAY place the Crew Tray": it is theirs to place, and
+      // nobody else's to place for them.
+      if (pending.player !== player) return 'NOT_YOUR_EXTRA';
       if (s.freeTrays.length === 0) return 'NO_FREE_TRAY';
       const where = resolveExtraStart(s, player, i);
       if (typeof where === 'string') return where;
@@ -2254,7 +2258,8 @@ export function reduce(s: GameState, e: GameEvent): void {
     }
 
     case 'extraQueued':
-      s.pendingExtras.push(e.trainNumber);
+      // §7 hands this train to the player who played the card, so the queue records them.
+      s.pendingExtras.push({ trainNumber: e.trainNumber, player: e.player });
       break;
 
     case 'secondSectionOrdered':
@@ -2284,11 +2289,14 @@ export function reduce(s: GameState, e: GameEvent): void {
      */
     case 'extraStarted': {
       const trayId = s.freeTrays.pop()!;
-      s.pendingExtras = s.pendingExtras.filter((n) => n !== e.trainNumber);
+      s.pendingExtras = s.pendingExtras.filter((x) => x.trainNumber !== e.trainNumber);
       const { direction } = e;
       const base = {
         id: trayId, trainNumber: e.trainNumber, trainIsExtra: true, engineAt: 0,
         consist: [] as RollingStock[], direction, movesUsed: 0,
+        // The queue is emptied here, before a single car goes on, so the tray carries the owner
+        // from now on — §7 lets the player who played it load the consist as they choose.
+        builtBy: e.player,
       };
       // Which way the tray physically points, for the cards it will pick up. A Division Point start
       // does not set it: those trays have never carried a facing and `enterMainline` does not read

src/engine/content.ts

@@ -504,8 +504,9 @@ export type MainlineKind =
   | 'uncontrolledSiding' | 'tunnel' | 'trestle' | 'interchange';
 
 /**
- * Speed as printed. `60` and `30` appear on the cards; Hilly prints P60/F30, and Heavy Grade
- * prints "G" with the player setting orientation.
+ * Speed as printed. `60` and `30` appear on the cards; Hilly prints P60/F30, and Heavy Grade prints
+ * "G" — no number at all, plus "Player sets orientation", **which the game deliberately does not do**
+ * (see `gradeReduction` below, and implications.md §10 Q11).
  *
  * WHAT THESE NUMBERS MEAN IS NOT YET SETTLED — see implications.md §10 Q2. Transcribed as data so
  * the answer can be applied without re-reading the cards.
@@ -531,6 +532,14 @@ export const MAINLINE_PROFILES: readonly MainlineProfile[] = [
   { kind: 'plains', name: 'Plains', speed: { kind: 'uniform', value: 60 }, trainsMayPass: false, sortsCars: false, entryPoints: ['start'] },
   { kind: 'curves', name: 'Curves', speed: { kind: 'uniform', value: 30 }, trainsMayPass: false, sortsCars: false, entryPoints: ['start'] },
   { kind: 'hilly', name: 'Hilly', speed: { kind: 'byTrainType', passenger: 60, freight: 30 }, trainsMayPass: false, sortsCars: false, entryPoints: ['passenger', 'freight'] },
+  /**
+   * `entryPoints` is TRANSCRIBED, NOT READ — nothing anywhere reads this field on any profile, and
+   * the printed start positions are not modelled: `crossingStages` counts Stages instead. Recorded
+   * here because implications.md §6 describes the card as having FIVE distinct starts (plain,
+   * brakemen, airbrakes, plain, helpers) against the four listed, and that discrepancy should be
+   * settled against `Mainline Cards.pdf` if the starts are ever implemented — not quietly "fixed"
+   * now, when nothing depends on it either way.
+   */
   { kind: 'heavyGrade', name: 'Heavy Grade', speed: { kind: 'grade' }, trainsMayPass: false, sortsCars: false, entryPoints: ['start', 'brakemen', 'airbrakes', 'helpers'] },
   { kind: 'doubleTrack', name: 'Double Track', speed: { kind: 'uniform', value: 60 }, trainsMayPass: true, sortsCars: false, entryPoints: ['start'] },
   { kind: 'uncontrolledSiding', name: 'Uncontrolled Siding', speed: { kind: 'uniform', value: 60 }, trainsMayPass: true, sortsCars: false, entryPoints: ['noPass', 'passingTrains'] },
@@ -664,12 +673,24 @@ export function mainlineDescription(kind: MainlineKind, gradeUp: Direction = 'ea
 }
 
 /**
- * Q11, answered: the Heavy Grade card prints "(Up)" and "Player sets orientation", so which way it
- * climbs is a property of the placed card, not a constant. `gradeUp` is the direction a train is
- * travelling when it goes UPHILL; a train heading the other way is descending.
+ * WHICH WAY THE GRADE CLIMBS, AND WHY NO PLAYER CHOOSES IT.
+ *
+ * Q11, answered from the card: Heavy Grade prints "(Up)" and "Player sets orientation", so the climb
+ * is a property of the PLACED CARD rather than a compass constant. `gradeUp` is the direction a train
+ * is travelling when it goes UPHILL; a train heading the other way is descending.
+ *
+ * **The second half of that print is deliberately overridden.** No player sets it — `setup.ts` rolls
+ * it from the seed. Settled v0.5.0 and re-confirmed 2026-08-23 after the question was raised again:
+ * a Heavy Grade always sits BETWEEN two districts (or beyond an end Division Point next to one),
+ * never inside one player's own, so there is no player with a fair claim to the choice — and the
+ * choice is not cosmetic, because it decides which of the three modifiers below can ever pay and
+ * therefore which direction of traffic is favoured, permanently. Giving it to the Superintendent was
+ * considered and rejected in that re-examination: the office rotates every three Stages, the
+ * advantage does not. Full reasoning in implications.md §10 Q11.
  *
  * Each applicable card takes a Stage off, never below one: a train cannot cross in no time.
- * Airbrakes only counts when Brakeman is already there, which the placement rule enforces.
+ * Airbrakes only counts when Brakeman is already there, which the placement rule enforces
+ * (`MAINLINE_MODIFIER_RULES`, `requiresOnCard`).
  */
 function gradeReduction(
   profile: MainlineProfile,

src/engine/intents.ts

@@ -258,6 +258,8 @@ export type RejectionCode =
   | 'NO_EMPTY_COACH_IN_YARD'
   | 'NOT_A_CONTROL_POINT'
   | 'NO_EXTRA_PENDING'
+  /** §7 gives an Extra to the player who played the card; another seat may not place it for them. */
+  | 'NOT_YOUR_EXTRA'
   | 'NO_FREE_TRAY'
   | 'NO_FREE_AD_TRACK'
   // -- §7, where an Extra may be started (`resolveExtraStart`)

src/engine/legal.ts

@@ -79,7 +79,7 @@ function candidates(s: GameState, player: PlayerIndex): Intent[] {
       out.push(...localOpsCandidates(s, player));
       break;
     case 'newTrain':
-      out.push(...newTrainCandidates(s));
+      out.push(...newTrainCandidates(s, player));
       break;
     case 'loadUnload':
       out.push(...loadUnloadCandidates(s, player));
@@ -257,7 +257,7 @@ function localOpsCandidates(s: GameState, player: PlayerIndex): Intent[] {
   return out;
 }
 
-function newTrainCandidates(s: GameState): Intent[] {
+function newTrainCandidates(s: GameState, player: PlayerIndex): Intent[] {
   const out: Intent[] = [];
   for (const [trayId] of s.trays) {
     for (const carType of CAR_TYPES) {
@@ -279,7 +279,9 @@ function newTrainCandidates(s: GameState): Intent[] {
    * is placed. In the middle of the railroad — an Interchange, a Control Point — both ways are real
    * runs, so those are offered twice, once per direction.
    */
-  for (const trainNumber of s.pendingExtras) {
+  // Only the player who played it is offered anywhere to put it (§7) — `check` refuses anyone else
+  // with NOT_YOUR_EXTRA, and offering options that are certain to be refused is how a menu lies.
+  for (const { trainNumber } of s.pendingExtras.filter((x) => x.player === player)) {
     for (const side of ['west', 'east'] as const) {
       out.push({ type: 'newTrain.startExtra', trainNumber, start: { kind: 'divisionPoint', side } });
     }

src/engine/setup.ts

@@ -254,7 +254,11 @@ function buildDivision(players: number, rng: Rng): DivisionNode[] {
        * district — so whichever direction climbs advantages one neighbour over the other, and there
        * is no single player who owns that call fairly. Orientation is rolled from the seed instead,
        * identically for solitaire and multiplayer, and this is not expected to change when setup
-       * eventually gains an interactive phase for other decisions. See implications.md §10 Q11.
+       * eventually gains an interactive phase for other decisions.
+       *
+       * RE-CONFIRMED 2026-08-23, when the question was raised again and giving the choice to the
+       * Superintendent was considered and rejected — the office rotates every three Stages, the
+       * advantage it would hand out does not. See implications.md §10 Q11.
        */
       node.gradeUp = rng.nextInt(2) === 0 ? 'east' : 'west';
     }

src/engine/state.ts

@@ -371,6 +371,15 @@ export type CrewTray = {
    * bug `isBeingMadeUp` was tightened to kill, and an arriving train never carries this.
    */
   beingMadeUp?: boolean;
+  /**
+   * WHOSE TRAIN THIS IS TO BUILD, for an Extra only.
+   *
+   * §7's Extra is loaded by the player who played the card, not by the Superintendent-first round
+   * that fills a Timetabled train — so the tray has to remember them: `pendingExtras` is emptied the
+   * moment the Extra starts, which is before a single car goes on. Undefined on every Timetabled
+   * train, where the round decides instead.
+   */
+  builtBy?: PlayerIndex;
   /**
    * WHERE THE ENGINE SITS IN THE TRAY, as an index into `consist`.
    *
@@ -831,8 +840,15 @@ export type GameState = {
   /**
    * §7 — Extra Trains played from hand, waiting for a free Crew Tray. An Extra is not scheduled:
    * it runs once, immediately, then its card goes to the Salvage Yard (§2.3).
+   *
+   * CARRIES WHO PLAYED IT (2026-08-23, Jesse's call). §7 gives an Extra to the player who played the
+   * card — "may place the Crew Tray at either Division Point ... and may load the consist as he
+   * chooses" — which is a different rule from the Timetabled make-up round, where the table goes
+   * round starting at the Superintendent. This was a bare `number[]`, so the engine could not tell
+   * whose Extra it was and asked whoever the acting order happened to be on: correct in solitaire,
+   * where there is only one player, and wrong at every table.
    */
-  pendingExtras: number[];
+  pendingExtras: { trainNumber: number; player: PlayerIndex }[];
   /**
    * Q9 — train numbers ordered to run a second section. The next New Train Phase makes up an
    * identical train behind the first, if a Crew Tray is free.