Monsters ride the wormhole; mental force fails loudly (rules rev 5)

Two findings from the first human-vs-Claude duel (room 9UA6). A
creature standing on a DIMENSIONAL WARP token had no way through it —
warpStep obeys only wizards. The new creatureWarpStep command steps a
commanded creature through the tokens under the walker's rules: one
move spent, solid stone refuses it, FEAR holds the beast, touch
effects greet whoever shares the landing; the board taps the paired
token like a rim mouth. Replay-safe ungated — a new command widens
nothing that was recorded.

MENTAL FORCE ate its card silently when the destination lay beyond
the victim's three walked spaces — the caster spent an attack and
learned nothing (ask me how I know). Rev 5 refuses the impossible
destination up front with the card kept; when the victim slips out of
range between cast and resolution, a mentalForceFizzled event tells
the table what happened instead of nothing. All 20 production ledgers
verified, the duel's own among them; 283 tests.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015RCWSTnb1KYTPyL4GmhGnF

packages/engine/test/casting.test.ts

@@ -1140,3 +1140,29 @@ describe("stone dead counts only the stones in play", () => {
     expect(state.players.find((p) => p.id === defender)!.life).toBe(12);
   });
 });
+
+describe("MENTAL FORCE respects the victim's three walked spaces", () => {
+  it("a destination beyond the walls is refused up front, card kept", () => {
+    let { state } = newGame();
+    state = toRound2(state);
+    const caster = activePlayer(state);
+    const victim = state.players.find((p) => p.id !== caster.id)!;
+    caster.position = { x: 0, y: 0 };
+    victim.position = { x: 2, y: 4 };
+    // Seal the victim into their square: every walked space is out of
+    // reach, so ANY other destination is beyond three moved spaces.
+    for (const side of SIDES) {
+      state.edgeOverrides[edgeKey(victim.position, side)] = "wall";
+    }
+    const mf = giveCard(state, caster.id, "mental-force", "MF");
+    const far = { x: 4, y: 9 };
+    const refused = applyCommand(state, caster.id, {
+      type: "cast", instanceId: mf.instanceId,
+      target: { kind: "player", playerId: victim.id }, params: { cell: far },
+    });
+    expect(refused.ok).toBe(false);
+    if (!refused.ok) expect(refused.error).toContain("three moved spaces");
+    // The card is still in hand — nothing was spent on the refusal.
+    expect(state.players.find((p) => p.id === caster.id)!.hand.some((c) => c.instanceId === mf.instanceId)).toBe(true);
+  });
+});