COINCIDENCE

COINCIDENCE is a gunnery duel on the North Sea, 1916. You are the officer in the director top of a battlecruiser, and you never touch a gun. You set two numbers — range and deflection — and pull the trigger on a four-shell salvo that then spends the next twenty seconds in the air.

There is no hit marker. There are four white columns of water, and you read them.

• SHORT — the columns stand clear in front of her. Come up.
• OVER — her hull cuts across their feet. Come down.
• STRADDLE — some short, some over. That is where the hits live.

Correct, fire, wait, read, correct again. Walk them on. That is the whole game, and it is enough, because the enemy's fire-control is doing exactly the same arithmetic to you, and getting better every salvo.

How to play

Four keys. ↑ ↓ range, ← → deflection, SPACE fire, A D helm. R opens a split-image coincidence rangefinder that gives you a noisy assist — the further out and the mistier, the more it lies to you. Press H or ? at any time for the full controls.

Three ships come out of the mist in turn: a light cruiser, an armoured cruiser, and finally a battlecruiser that shoots exactly as well as you do. Sink all three to win. Take enough shells in return and your list passes twenty degrees, the sea comes over the barbette, and it is over.

The twist

The defence is the helm. Steer toward their last cluster of splashes — chase the salvos — because their correction moves away from where they just landed. It genuinely works: in the tuning harness, chasing took 8.9 hits across a battle where steaming straight took 14.4 and blind zigzagging took 18.3. But every turn you make also spoils your firing solution, because your rangekeeper is holding a range rate that your own rudder just invalidated. Safety costs accuracy. That is the whole tension.

Damage is geometric, not a health bar. Where a shell lands along the hull decides what it wrecks: bow and stern flood and put you over on your ear, machinery hits cost speed and pour black smoke, a turret hit means your next salvo is three shells instead of four — and a magazine hit ends a ship in one column of flame. Shooting at 16,000 yards means shells falling at a steep angle with a narrow danger space; closing to 6,000 means flat, forgiving trajectories and a much better chance she does the same to you.

How it was made

Conceived and written by Claude Fable 5, built by Claude Opus 5, in one automated run. No scripted flight times: shells are integrated at 1/120 s under gravity and quadratic drag through an exponential atmosphere, with a drifting crosswind pushing them the whole way — twelve kilometres comes out at 20.1 seconds of flight, arriving at 11.6° when it left at 7.8°. The enemy runs the identical solver off a lagging plot of your course, which is why chasing salvos works at all. Every number quoted above was measured by extracting the shipped simulation core into a harness and fighting sixty battles per configuration. A second pass rebuilt the renderer around cached plates and sprites after the first build only held 16 fps on a retina screen; it now holds 60.