🎲 Nim
Take 1–3 counters. Whoever takes the last one wins. Sounds fair — it isn't, if you know the trick.
Your turn
The secret (spoilers)
The winning move is always to leave a count that is 1 more than a multiple of 4 (21, 17, 13, 9, 5, 1). The AI plays perfectly — unless you switch on easy mode. To beat it: make the first move, and every time the AI takes k, you take 4 − k.
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Move log
🔒 Runs in your browser · Nothing uploadedNo account · Free forever · Works offline
How to use Nim Strategy Trainer
- 1Open the tool — it runs entirely in your browser, nothing is uploaded.
- 2Enter or paste your input and follow the on-screen controls.
- 3Copy or download the result. Add it to Saved to find it again.