Cairo

Cairo, by Mark Thompson

There are 32 ways to color the five edges of a pentagonal Cairo tile in two colors, and a set of such tiles (as shown below) form the pieces of this game. The players are Blue and White; Blue starts with the 16 tiles that have three or more blue edges, and White with the tiles that have three or more white edges. The playing board, shown below, is a squarish field of 32 cells with two opposite edges colored blue and the other two white.

In each turn, a player places a tile onto the board in such a way that none of its edges touch a tile (or edge of the board) with the opposite color. Every tile placed that matches one edge with a tile already played (or edge of the board) scores two points; if it matches two edges, it scores three points; if it matches three edges, five points; four edges, ten points; five edges, 15 points.

The highest point score when neither player can play any more wins.

I’ve never played this game. Consequently its rules will probably need adjustment, especially the point values of matching different numbers of edges, which is currently arbitrary. Perhaps it would introduce some subtlety to the game if: 1) a player who can make a play that matches four or five edges is required to do so, and 2) playing a tile that matches four or five edges has a large negative score. Thus a player could lay traps for his opponent.

Perhaps a player who cannot match more than two or three edges should be allowed to play a tile where one or more edges don’t match, but mismatching edges count against the matching edges.

If you play Cairo and have comments, please let me know!


	Questions, corrections, comments: Send me e-mail at markthom@flash.net


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