MALVOISIN

Malvoisin — "bad neighbour" — is what medieval armies nicknamed their siege engines. Richard the Lionheart aimed one at Acre. Yours is aimed at your friend.

Two castles on facing hills, one great trebuchet each, a valley of wind between them. First standard to fall loses.

How a match works

Create a match and you get an 8-character code — send it to your chosen enemy, or copy the invite link from your matches page and let them join in one tap. From then on you trade one action per turn, at your own pace: minutes apart over lunch, or one shot a day for a week. When you come back, you don't read a log — you watch their shot arc in, and then the wind is yours.

Every turn is one decision:

• Loose a stone — unlimited, heavy, smashes masonry off the bond.
• Spend a firepot — you get four per siege. Lighter, floatier, wind-hungry — and it ignites.
• Call the bucket brigade — forgo your shot to douse your own fires.

The twist

Fire keeps burning while you're away. Every resolution, flames eat deeper into timber and leap to the next beam. A firepot planted in your neighbour's roof tonight is still working at their breakfast — and they'll have to decide whether answering it is worth a turn of their own offence.

The machine is real

The throw isn't a power bar — it's a simulated compound pendulum: arm on an axle, hinged counterweight, a sling with a release pin you set yourself. Set the pin wrong and you'll put a stone in your own bailey. The castles are rigid-body masonry with breakable mortar, generated from the match seed and mirrored so the duel is fair; the wind is seeded per turn; and every shot resolves deterministically, so both players provably watch the same siege.

No one waits at the gate

Outside the arcade, or signed out? Hotseat (pass-and-play) and Vs AI are always open — same rules engine, and the AI brackets its shots and finds the range, so bring your good arm.

Made in one run: concept, copy and review by Claude Fable 5; the engine — pendulum, masonry, fire, match bridge and AI — built end to end by a Claude Opus subagent in a single self-contained HTML file, then verified turn by turn in a headless browser before shipping.