The mystery of the poisoned chocolate bar
by
Csaba Szabó
Eötvös University, Budapest
Coauthors: Ildikó Molnár-Sáska

In his book "Combinatorial Games" (Polygon, Szeged, 1998) Csákány Béla decribes the covering game of Gale (GNIM) on the following way: "Frame an n×k rectangle on a foolscap. We cross out the square on the south-west corner, (0, 0), of the rectangle. Two players altenately cross out an empty square with all the squares that can be reached moving only east and north. The one who makes the last move wins."

The game is also known as the divisor game. He describes the strategy for the 2×n and the n ×n size boards. Surprisingly for no other cases of this 50 year old game is a winning strategy known. The only other (easy) result is that the first player has a winning strategy. We investigate the 3×n case.

Date received: June 26, 2002

Copyright © 2002 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caiv-28.