How to play
On each turn, remove any number of matches from one row only. Choose the usual rule where the final match wins, or the misère version where taking the final match loses.
One or two players · about 3 minutes
Nim
Three little rows of matches, one very old mathematical trap.
PlayPilesRule
Blue goes first.
Choose one or more matches from one row, then take them.
The hidden depth
Nim looks like pure intuition, but there is a complete mathematical strategy underneath it. Children can discover patterns long before they know the binary arithmetic behind them.
Change only one row
Every move must remove one or more matches from a single row. If you are learning the game, pause before each move and compare the sizes of all the rows, not just the largest one.
A little more
A game with a hidden solution
Nim is one of the classic examples of a game that looks intuitive but has a complete mathematical strategy. The Perfect computer knows it. Playing a few rounds is a good way to start discovering the pattern yourself.