Hexapawn

This is an adaptation of Hexapawn, a board game originally developed by Martin Gardner in 1962, for the SEGA Master System.

Hexapawn is played on a 3 x 3 board, with three chess pawns on each side. Only two types of movment are allowed:

1. A pawn may advance straight forward one square to an empty square;
2. A pawn may capture an enemy pawn by moving one square diagonally, left or right, to a square occupied by the enemy.

The game is won in any of three ways:

1. By advancing a pawn to the third row.
2. By capturing all enemy pieces.
3. By achieving a position in which the enemy cannot move.

The game is played against HER (Hexapawn Educable Robot). At first HER has no strategy, but it will learn not to repeat the same move that led to a defeat.

In the original board version of the game, HER is constructed with 24 matchboxes, each depicting one possible board pattern reachable on the 2nd, 4th, or 6th turn. For each pattern, possible movements are marked with colored arrows, and inside each box there is one single colored bead matching the colors of the movements. The machine movement is determined by drawing one bead from the box. If the machine loses, the last bead drawn is removed from the box, so it won't repeat that same movement in future matches. The machine learns to play a perfect game after losing about 11 games.

This version was developed using devkitSMS and it was based on the BASIC implementation published in the 1978 book BASIC Computer Games.