Chess Visualization with Aiden Rayner

🧠🧠 Nimble Knight (Illegal Move Exercise)

February 20th, 2026

Illegal Move Exercise: The audio will lead you through a series of moves from the beginning of a game. Somewhere in there, a player will make an illegal move but the game will continue anyway. Find the illegal move.

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PGN for today's exercise:

  1. Nf3 c5 2. c4 Nf6 3. Nc3 Nc6 4. d4 cxd4 5. Nxd4 e5 6. Ndb5 d6 7. g3 Be7 8. Bg2 a6 9. Na3 Be6 10. O-O h5 11. Bg5 Qd7 12. h4 Ng4 13. Rad1 Bxg5 13. hxg5 h4 14. gxh4 Rxh4 15. c5 d5 16. Nxd5 *

And the answer is...
White's move 13. Rad1 is illegal because the white Queen is on d1.