Four colours and four sizes of polyominoes share a growing grid. Each placement must differ in colour and size from the last move and from every orthogonally touching piece. The last player able to place wins.

Inventor: Stephen Tavener

Published listing: BoardGameGeek: Four.

Only sizes 1–3 (no 2×2). Bounding box 7×7 (simplified).

• Current engine version: 20240216 (2024-02-16). On Abstract Play since 2024-02-18.

• https://boardgamegeek.com/boardgame/133842/four