Editing Hexapawn (section)

{{Short description|Two-player game invented by Martin Gardner}}
{{#invoke:chessboard mxn|board|cols=3|rows=3
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|pl|pl|pl
| 3x3 Hexapawn setup
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{{Chess diagram 4x4
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|pd|pd|pd|pd
|  |  |  |
|  |  |  |
|pl|pl|pl|pl
| 4x4 Octopawn setup
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'''Hexapawn''' is a [[deterministic game|deterministic]] two-player [[game]] invented by [[Martin Gardner]]. It is played on a rectangular board of variable size, for example on a 3×3 board or on a regular [[chessboard]]. On a board of size ''n''×''m'', each player begins with ''m'' [[pawn (chess)|pawn]]s, one for each [[Square (geometry)|square]] in the row closest to them.  The goal of each player is to either advance a pawn to the opposite end of the board or leave the other player with no legal moves, either by [[stalemate]] or by having all of their pieces captured.

Hexapawn on the 3×3 board is a [[solved game]]; with perfect play, White will always lose in 3 moves (1.b2 axb2 2.cxb2 c2 3.a2 c1#). Indeed, Gardner specifically constructed it as a game with a small [[game tree]] in order to demonstrate how it could be played by a [[heuristic]] [[Artificial intelligence|AI]] implemented by a [[mechanical calculating device|mechanical computer]] based on [[Donald Michie]]'s [[Matchbox Educable Noughts and Crosses Engine]] (MENACE). 

A variant of this game is '''octopawn''', which is played on a 4×4 board with 4 pawns on each side. It is a forced win for White. 

Only 24 matchboxes are required for a hexapawn version of [[Matchbox Educable Noughts and Crosses Engine]].