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G4G8 Exchange Book

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Each of our two-person games is a word version variation from the tic-tac-toe or noughts and crosses family. It is well known that classic tic-tac-toe is a draw when expertly played. It is also clear that not all of its plays are equal- a strong move for the first player is to initially take the powerul center square. ASTEROID and ASTEROID II, on the other hand, are both completely symmetric (in the sense that all letters are used equally) and each have rather suble forced wins for either the first or second player.


This is an electronic copy of a paper originally appearing in the G4G8 Exchange Book. Archived with permission. The author(s) reserves all rights.


Gathering for Gardner inspires fun and wonder for recreational mathematics, magic, puzzles, and art. The G4G Gift Exchange is an integral part of the Gathering 4 Gardner meetings. Each attendee is asked to participate in the G4G Gift Exchange.

The G4G Exchange Book is for those who wish to submit papers as their exchange gift and also for those who wish to include descriptions, instructions, solutions etc. related to their physical gifts.