Droid Nim is a game that challenges the mind while illustrating some advanced mathematical ideas. It can be difficult to defeat the computer if you don't know what you're doing, and even if you do, one slip-up can cost you the game. Based on the classical game of Nim, this version lets you vary the number of rows and "pebbles" in each row, as well as choose between normal play or misere play. The computer has a bit of an attitude, so when you get tired of its beating you, find a friend with Bluetooth and try to play one-on-one. A detailed help explains the game, describes the options, and gives offers pointers on how to develop a winning strategy.