Experience the timeless wisdom of game theory · the classic 3·5·7 setup
Classic 3·5·7: 3 piles with 3 / 5 / 7 stones
Tip: in the 3·5·7 setup the first player wins with perfect play
Nim is one of the most celebrated classical games in combinatorial game theory, and is said to have originated in China. This edition uses a 3-pile setup: 3 · 5 · 7.
You and your opponent alternate turns. On each turn, remove at least 1 stone from any single pile. The player who takes the last stone wins.
You and the system alternate turns. You cannot skip a turn, and you cannot take zero — every move must remove at least 1 stone from some pile.
When every pile is empty, the player who took the last stone wins. This is the standard Normal Play convention.
Classic 3 · 5 · 7 setup: 3 piles of 3, 5, and 7 stones. The first player can force a win simply by keeping the Nim-sum ≠ 0.
During play, the 💡 Hint toggle in the top-right will tell you exactly which pile and how many stones to take. It is recommended that you keep it on while learning — follow the suggestion to win, then turn it off whenever you are ready to challenge yourself!