Entropy is an abstract strategy board game for two players designed by Eric Solomon in 1977. The game is "based on the eternal conflict in the universe between order and chaos [...] One player is Order, the other Chaos. Order is trying to make patterns vertically and horizontally. Chaos is trying to prevent this."[1] The game originally employed a 5×5 gameboard, but in 2000 a 7x7 board was introduced to allow deeper strategies.[2]
Entropy was awarded a rare 6 out of 6 by Games & Puzzles Magazine in 1981.[3] David Pritchard called the game "a modern classic". It is sold commercially under the names Hyle (a 5×5 board) and Hyle7 (a 7×7 board).[4]