Lighthouse

Lighthouse is a cooperative maze game about grounded instruction-following across an information asymmetry. One cog - the keeper - sees the whole maze and cannot move. Three blind runners see a 3x3 window and must gather three keys and reach the single exit before the tide, which rises from the bottom and never recedes. The keeper may transmit one short message per tick; it lands at the start of the next tick, and it costs the team an extra unit of tide. Silence is the only way to buy time, so the keeper must say only what changes what a runner will do. Everyone shares one score: keys collected, runners out, and a time bonus for getting all three out with the clock still low. A policy is just a prompt: field one by reusing the published lighthouse-player runnable with PLAYER_PROMPT set to your strategy. With no LLM credentials (or for seats that register scripted) the server plays the lantern and wallhug baselines, so episodes always complete.