Mr. Squares left you his property.

You discover a mysterious chest locked with a seven-letter combination lock.

On the chest, an engraved checkerboard with a game's worth of chess moves:

Game Algebraic notation:

1. e4 e5 2. d3 d5 3. exd5 Qxd5 4. Be3 Nc6 5. Nf3 Bc5 6. Be2 Bg4 7. Bxc5 Qxc5 8. h3 Bxf3 9. Bxf3 Nf6 10. a4 a5 11. g4 g5 12. Bg2 Nd4 13. b3 Rd8 14. Bxb7 Nxc2+ 15. Kd2 Qxf2+ 16. Kc1 Qe2 17. Qxe2 Nxa1 18. Bc6+ Nd7 19. Rf1 f6 20. Bxd7+ Rxd7 21. Qe4 Rf8 22. Qg2 Rxd3 23. Qc6+ Ke7 24. Qg2 Rfd8 25. Rf5 R8d6 26. Qf1 c5 27. Qe2 Ke6 28. Qb2 Rd1#

Game UCI notation:

e2e4, e7e5, d2d3, d7d5, e4d5, d8d5, c1e3, b8c6, g1f3, f8c5, f1e2, c8g4, e3c5, d5c5, h2h3, g4f3, e2f3, g8f6, a2a4, a7a5, g2g4, g7g5, f1g2, c6d4, b2b3, a8d8, g2b7, d4c2, d1d2, c5f2, e1c1, f2e2, d1e2, c2a1, b7c6, b8d7, f1f1, f7f6, c6d7, d8d7, e2e4, f8f8, d1g2, d7d3, g2c6, e8e7, c6g2, f8d8, f1f5, d8d6, g2f1, c7c5, f1e2, e7e6, b2b2, d3d1

Game interactive board: Chess Stack Exchange Snippet

Looks like a real game, but at the same time something feels weird.

Intrigued, you re-read the welcome letter you were given.


I baked some cookies. Carefully remove all the pieces from the oven. I do not want to walk over any crunchy bits on the kitchen floor.

Keep this as key information.


T. Squares

Oh, what a simple man.

Find the seven letter English word to open the chest.


Moving words in the letter reveal the secret of the chess moves.

  • 1
    $\begingroup$ This seems to be too open for interpretation. I think you should at least provide a way to confirm that the answer is certainly correct. For example stating the length of the password or some flavor text with subtle hints. $\endgroup$
    – PDT
    Commented Apr 14 at 4:50
  • 1
    $\begingroup$ @PDT thanks for the heads up, I've added now some more flavor and a way to confirm the solution. $\endgroup$
    – Vepir
    Commented Apr 14 at 7:51
  • $\begingroup$ @Vepir is the [computer] tag suitable here? $\endgroup$ Commented Apr 14 at 11:20
  • 2
    $\begingroup$ -1. This is too close to "guess what I'm thinking". And because your picture is animated, I scrolled down so as to hide it, and that thereby hides all your text. $\endgroup$
    – Rosie F
    Commented Apr 14 at 14:04
  • 1
    $\begingroup$ @quarague it doesn't work on Puzzling, but you can make use of their sandbox as a reference for Puzzling questions (this purpose is written in the link I put) $\endgroup$
    – justhalf
    Commented Apr 16 at 16:43

1 Answer 1


The hidden word is


It is concealed in:

The colors of the squares where each piece moves to, encoded using the 8-bit ASCII text encoding. The white squares are zeros and the black squares are ones. Discovering this was a lucky guess for me.

The intended solution might have been to step through the game in the replayer and record the color of each square every piece moves to. I did it using text manipulation: Start with the UCI notation. Remove the first two letters of each group to get e4, e5, d3, .... Substitute abcdefgh12345678 with 0101010101010101 to get 01, 00, 10, .... Next, replace 01, and 10, with 0, and replace 00, and 11, with 1. This yields the binary string 01000010010011000101010101001110010001000100010101010010 which decodes to BLUNDER using 8-bit ASCII.

  • $\begingroup$ Nice! Using the hint was supposed to reveal "rot13(cvrprf jnyx bire ovgf ba gur fdhnerf)". The latest edit to the letter was a clue: rot13("nf xrl vasbezngvba" fbhaqf yvxr "nfpvv vasbezngvba"). The main letter clues: rot13(Erzbir nyy cvrprf orpnhfr bayl purpxreobneq znggref. Jnyx bire (pehapul) ovgf orpnhfr rvgure oynpx be juvgr (xvgpura sybbe) gvyrf / fdhnerf (rapbqr vasbezngvba). Ynfgyl, znlor gur "Olr, G. Fdhnerf" fbhaqf yvxr "olgr(f) (va) fdhnerf.") $\endgroup$
    – Vepir
    Commented Apr 21 at 7:36

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