Playable with a standard chess set.
Easy to learn.
Difficult for computers (the $10,000 programming challenge is still available).
Fun and interesting for humans.
The creation of Arimaa was inspired by the Deep Blue vs Gary Kasparov match in which the computer defeated the world chess champion. Arimaa was created to show that humans can still outplay computers using a chess set and provide the next challenge to the AI community.