Matchsticks

Matchsticks is a puzzle game for two players. Several matchsticks are placed in a line and players take turns removing one, two, or three matches from the table. You can't take any more than three matches on any one turn, you have to take at least one, and you can never put any back. The object is either to take the last match or force your opponent to take it. It's more of a puzzle than a game, for if one player knows the secret, it is either difficult or impossible for the other player to win, depending on how the game starts.

For this online version of the game, the computer "knows" the secret. It is a puzzle, therefore, to figure out how to beat it. When you discover the secret, you can play the game against an unwitting friend and flaunt your ability to win it repeatedly.

Source: The Game Website.