Trebuchet Castle Siege

You are a siege engineer on a hill outside somebody else's walls. You have one counterweight trebuchet, a limited train of ammunition, and a castle built out of several hundred individually mortared stones.

The engine

The trebuchet is laid, not aimed. Four numbers decide where the stone goes and you set every one of them by hand:

Control	What it does
A / D	Swing the frame.
W / S	Wind the counterweight between 500 kg and 3 tonnes.
Q / E	Set the release angle, 30° to 70°.
SPACE	Hold to winch the arm down. Let go and it looses.
1–5, R	Pick the shot on the belt; R is the free ranging stone.
RMB / arrows, scroll, F, C	Orbit, zoom, follow the shot, recentre.

Releasing early leaves the arm cocked shallow, and a shallow cock has less drop to spend — an impatient shot genuinely falls short.

The arc is integrated properly: gravity, quadratic drag on airspeed, and a wind that rerolls every siege. The predicted range on the HUD is the same integrator the stone will fly, so it never lies to you — it just cannot see the wall you are about to hit.

The castle

Every castle is built stone by stone in a running bond, and every stone is a rigid body that starts mortared and immovable. A hit breaks the mortar in a radius; whatever those stones were carrying loses its bed and comes down on its own; and everything after that is physics — falling masonry knocking over its neighbours, spans shearing off, rubble piling into a berm the next shot has to plough through.

Integrity is the fraction of the castle still mortared. Bring it to 25%, breach the keep, and put the Castle Lord off his balcony.

The shot

Ammunition	Breaks wall	Clears crews	Notes
Ranging Shot	—	—	Free, and cut to a boulder's weight so it calibrates honestly.
Boulder	5.0 m	3.0 m	The wall-breaker.
Firepot	2.6 m	5.4 m	Light damage; the fire spreads through timber and cooks crews.
Grapeshot	2.2 m	8.5 m	Barely dents stone. Shreds everything standing on it.
Plague Cow	3.4 m	10.0 m	Kills the garrison and leaves the masons too sick to build.

The garrison

Wall archers chip away at your frame — collapse their span or grapeshot it. Ballista towers hit far harder — shatter the tower base and the engine goes with it. Repair masons walk out to breaches and re-mortar what you knocked loose — burn them out, or breach faster than they build. Past 55% integrity the gate opens and sortie knights come up the road for your machine. And the Castle Lord jeers from his keep balcony while his masons work double time.

Five sieges

The Motte · Curtain Wall · Twin Towers · Concentric Castle · The Fortress. Each unlocks the next, along with the ammunition to take it. Best shot count and stars are kept in the world. There is also a Custom Siege for a skirmish: pick the castle, the wind, the ammunition and the size of the garrison.

Every sound in the game — the winch ratchet, the counterweight's WHOOMPH, the whistle of the stone, stone-crack and rubble-tumble, the war horn, the fanfare — is synthesised from scratch in siege_sfx and baked into the world.