The ancient stone-taking strategy game. Starting from a pile of 15 stones, take turns removing 1, 2 or 3 — whoever takes the last stone wins.
Rules
On your turn, click Take 1, Take 2 or Take 3 to remove that many stones from the pile.
The AI takes its turn immediately after.
Whoever removes the very last stone from the pile wins.
The AI plays a mathematically perfect strategy, so a mistake on your part is the only way it wins.
Tips
Always leave a multiple of 4 stones after your turn (15 → 12 → 8 → 4 → 0) and you're guaranteed to win — that's the entire winning strategy for a 15-stone pile with a take-1-to-3 rule.