Tarati
The abstract strategy board game by George Spencer-Brown, author of Laws of Form. Move, flip, and outmanoeuvre — free online.
What is Tarati?
Tarati is a two-player abstract strategy game designed by mathematician George Spencer-Brown as a practical application of the calculus of distinctions from his book Laws of Form. Its structure is minimalist, its consequences deep: you move pieces across a board of 23 vertices arranged in concentric zones, flipping enemy pieces to your own colour and promoting your own toward victory.
There is also Tarati Six, a separate multiplayer variant for 2 to 6 players on an expanded board with cubic pieces.
How you win
A piece moves to an adjacent free vertex and flips every eligible enemy piece it approaches from outside (the pre-adjacency rule — the game's key tactic). Reach the opponent's base and your Cob is promoted to a Rok, which moves freely in any direction. You win by capturing the last enemy piece in a single move (Mit) or leaving the opponent with no legal move (Stalemit).
Features
Online multiplayer
Matchmaking, Glicko-2 ranking, leaderboards, tournaments, challenges and a spectator mode.
Strong AI
Four difficulty levels and chess-style position analysis with an evaluation bar.
Interactive tutorial
Learn the rules step by step with guide bubbles on the board.
Everywhere
Play in the browser or install the app on Android, Windows, macOS and Linux.
Download & play
Laws of Form
Tarati is grounded in George Spencer-Brown's Laws of Form, a mathematically complete calculus built entirely on the concept of distinction. Tarati is the first serious digital game based on his work — a playable entry point into these ideas.