The fireball-then-buddy lockout

Per the owner's favorite play: the pact only breaks when its caster
attacks the target, so a blow landed BEFORE the pact leaves it intact.
After spending its attack, a non-berserker bot with BUDDY in hand signs
it onto the weakest visible unpacted enemy — the one it likely just
burned — barring their revenge. The berserker skips it: it would only
break its own pact tomorrow.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0138A8CjeQRpvzKxuMfz1Bqc

packages/engine/src/automaton.ts

@@ -1250,6 +1250,23 @@ export function automatonCommand(
     }
   }
 
+  // BUDDY after the blow: the wounded cannot come looking for payback —
+  // the pact holds unless the clockwork strikes them again. The berserker
+  // skips it; it would only break its own pact tomorrow.
+  if (tier.buffs && view.turn.attackUsed && style !== "berserker") {
+    const pact = inHand(view, "buddy");
+    if (pact) {
+      const sighted = sightedCellsFor(view);
+      const mark = livingEnemies(view)
+        .filter((p) => sighted.has(cellKey(p.position)) &&
+          !view.sustained.some((s) => s.cardId === "buddy" && s.casterId === you && s.targetId === p.id))
+        .sort((a, b) => a.life - b.life)[0];
+      if (mark) {
+        return { type: "cast", instanceId: pact.instanceId, target: { kind: "player", playerId: mark.id } };
+      }
+    }
+  }
+
   // March. The thief-chase outranks everything; the berserker hunts wizards
   // over gold; the worrier keeps its distance; the hunter goes to the gold.
   if (view.turn.movementUsed < view.turn.movementAllowance) {

packages/engine/test/automaton.test.ts

@@ -427,3 +427,43 @@ describe("round two of the owner's tactics", () => {
     if (!r.ok) throw new Error(r.error);
   });
 });
+
+describe("the fireball-then-buddy lockout", () => {
+  it("burns the target, then signs the pact so they cannot hit back", () => {
+    let { state } = createGame({ playerIds: ["bot", "other"], seed: 42, sets: ["basic", "expansion1"], deckRev: 24 });
+    for (let guard = 0; guard < 10 && !(actingSeat(state) === "bot" && state.turn.round > 1); guard++) {
+      const r = applyCommand(state, actingSeat(state), { type: "endTurn", draw: 0 });
+      if (!r.ok) throw new Error(r.error);
+      state = r.state;
+    }
+    const bot = state.players.find((p) => p.id === "bot")!;
+    const prey = state.players.find((p) => p.id === "other")!;
+    prey.position = { ...bot.position };
+    bot.hand = [
+      { instanceId: "fireball#T", cardId: "fireball" },
+      { instanceId: "buddy#T", cardId: "buddy" },
+    ];
+    // First: the blow.
+    let cmd = automatonCommand(viewFor(state, "bot"), "hunter", "archmage");
+    expect(cmd).toMatchObject({ type: "cast", instanceId: "fireball#T" });
+    let r = applyCommand(state, "bot", cmd!);
+    if (!r.ok) throw new Error(r.error);
+    state = r.state;
+    r = applyCommand(state, "other", { type: "pass" });
+    if (!r.ok) throw new Error(r.error);
+    state = r.state;
+    // Then: the pact.
+    cmd = automatonCommand(viewFor(state, "bot"), "hunter", "archmage");
+    expect(cmd).toEqual({
+      type: "cast", instanceId: "buddy#T",
+      target: { kind: "player", playerId: "other" },
+    });
+    r = applyCommand(state, "bot", cmd!);
+    if (!r.ok) throw new Error(r.error);
+    state = r.state;
+    // The pact holds: the victim cannot strike their tormentor.
+    expect(state.sustained.some(
+      (s) => s.cardId === "buddy" && s.casterId === "bot" && s.targetId === "other",
+    )).toBe(true);
+  });
+});