Every piece moves through all three dimensions.
An original abstract strategy game on a 5×5×5 lattice: 125 cells, five levels, seven piece types whose direction sets run through the whole volume. Not chess with a third axis bolted on — a rules system built for one from the first line.
Towers slide upward as readily as along a rank. Pawns capture diagonally and vertically. A check can arrive from a board you were not looking at, and a Sovereign with 26 neighbours is very hard to trap — which changes what a winning position even looks like.
The Sentinel is two posts at the 2:1 offset it leaps by. The Lancer is a spire whose edges face the body diagonals. The flat token is the spatial model seen from above, because a flat board is a plan — so you can read a piece you have never met.
No game engine, no chess library, no imported camera controls. The rules, the WebGPU renderer and Strata — the search engine that plays it — were written from scratch, under a constraint that was the point rather than an obstacle.
The figure above is one Regent standing at the centre of the lattice, with a line drawn along each of its twenty-six directions until that direction runs into a wall. It is generated from the same frozen direction tables the engine moves by — if a piece ever gained a direction, the picture would gain a line. Every piece has a figure like it on the rules page.
The game is complete and playable now: a full rules engine with check, mate, stalemate, promotion, repetition and the rest; five flat boards you can play entirely from the keyboard; a slice view for reading a vertical line of attack; a spatial projection when your browser can draw one; and a purpose-built opponent at four strengths. It works on a phone, and it works without WebGPU.
Free to play, and it needs nothing. No account, no install, no network after the page loads. The engine runs in a worker in your own tab.