A hexagonal go-like where pieces come in two types. Only pieces of opposite type are connected, and a 4-arc of pieces of the same type (regardless of colour) is forbidden.

Inventor: Hoembla

See Oonpia rules (PDF). Hex-hex board (default size 6). Pie rule. Stones are plain or dotted.

Board sizes 5–12 (default 6).

• Current engine version: 20260305 (2026-03-05). On Abstract Play since 2026-03-07.

• Cycle the piece type by clicking the same cell, or use the legend. Blocked cells: a translucent dot means only a dotted stone may go there; a translucent stone means only plain; both means fully blocked.

• https://github.com/th555/abstract_game_rules/blob/master/oonpia_rules.pdf