This book constitutes the thoroughly refereed post-proceedings of the 4th International Conference on Computers and Games, CG 2004, held in Ramat-Gan, Israel, in July 2004, and co-located with the 12th World Computer Chess Championship and the 9th Computer Olympiad.

The 21 revised full papers presented together with 1 keynote article were carefully selected during two rounds of reviewing and improvement from 37 submissions. The papers cover all aspects of artificial intelligence in computer-game playing. Topics addressed are evaluation and learning, search, combinatorial games and theory opening and endgame databases, single-agent search and planning, and computer Go.