Games 3Chess
3Chess
Three-player hex chess on a 127-cell board, derived from a formal axiom system.
3-player hex chess where calculation alone won’t save you.
3Chess is our first game. A three-player chess variant on a 127-cell hexagonal board, with three 120°-rotationally-symmetric territories. It is the only 3-player chess game derived from a formal axiom system.
At a glance
- 127-cell hexagonal board · three identical territories at 120° to one another
- 15 pieces per player · standard chess pieces, hex-adjusted geometry
- Cascading checkmate · a single move can mate two opponents at once
- 20-move rule · derived from NP1 proof; 3-player endgames stall faster than 2-player
- PL-Elo Exact rating · a custom 3-player rating model (Plackett–Luce closed form + σ tracking)
Where to play
- Free browser demo · 3chess.online/play
- Buy the full game · 3chess.online/buy · $9.99
- itch.io · roundonline.itch.io/3chess
Read more
- Rules · 3chess.online/rules
- Why three-player chess · 3chess.online/three-player-chess
- Axioms behind 3Chess · /axioms/3chess/ — game rules · rating · environment · online handshake · glossary
The studio behind it
3Chess is made by Round Online. We work axiom-first — see why.