Tabletop rules engines built around one constraint: the same seed and the same decisions always produce the same game. That makes a match rewindable, auditable, and cheap to run a thousand times.
A four-seat Commander table with a real priority-and-stack spine, so counterspells and instant-speed tricks work as they do in person. Card effects are compiled to deterministic instructions rather than interpreted, and any seat can be piloted by you or by an AI agent choosing among the engine's legal actions.
regathering.halfdreamt.usA scene host rather than a single game: a versioned ruleset, a content bundle, a seed, and an ordered command stream resolve to one exact outcome. Warhammer 40,000 Combat Patrol is the production ruleset, with Warcry and a Cypher System implementation alongside it.