Parity Tic-Tac-Toe
(Published on 1. March 2025, 08:18 by marty_sears)
- OVERALL GAME: Todd and Steven are playing a game of Tic-Tac-Toe in a sudoku grid, where they attempt to 'claim' each 3x3 box. It's a very close game, with one player claiming four boxes and the other claiming five. However, the winner isn't necessarily the player to claim most boxes. To win the overall game, a player must claim at least one straight line of three 3x3 boxes (horizontally, vertically or diagonally), without their opponent managing to get a line of three boxes themselves.
- CLAIMING A BOX: To determine who claims each 3x3 box, Todd and Steven play a mini game in each box. Todd places odd digits and Steven places even digits. A player claims a 3x3 box by getting at least one straight line of three digits of their parity (horizontally, vertically or diagonally) in that box, and without their opponent managing to get a line of three digits themselves.
Rules:
Normal sudoku rules apply. Entering correct digits may clear fog somewhere in the grid - no guessing is necessary.
Digits separated by a white dot are consecutive.
Digits separated by a black dot are in a 1:2 ratio.
Every 3x3 box has a definitive winner, and there is also a definitive winner of the overall multi-box game. But who is it?!
Please leave a comment if you enjoy :)
Solution code: Column 1, reading downwards
Comments
on 17. September 2025, 00:28 by bleppie
Beautiful and fun!
on 11. September 2025, 05:07 by Tuanzi
Very nice puzzle! I really enjoy it! Thank you!
on 22. May 2025, 23:39 by xardass
Awesome solve with a gripping narration to boot. I had a hunch who would win and was not disappointed :)
on 9. March 2025, 20:36 by poundcayx
Fantastic concept :)
on 6. March 2025, 10:10 by novato
As always, an astonishingly clever puzzle from Marty. A joy to solve.
on 5. March 2025, 23:43 by CFood
i was stuck for a good while cause somehow i missed "one player claiming four boxes and the other claiming five"
on 3. March 2025, 12:58 by madhupt
So p, so, so good! Phenomenal!
on 3. March 2025, 12:38 by Mennoo_
Moral of the story/puzzle: Both Todd and Steven are very bad tic-tac-toe players
Great puzzle Marty!
on 3. March 2025, 08:58 by Monkee
I have never been this invested in a Tic-Tac-Toe game before.
What a lovely puzzle!
on 3. March 2025, 02:23 by Logerfo
Thank you for publishing this puzzle, very creative, I loved it!
on 2. March 2025, 22:48 by PancakePie
Very pleasantly surprised by this beaut!
Fun to understand and internalize the logic. And the story! What a nail-biter. Thanks Marty!
on 2. March 2025, 19:24 by CorpJigsQuand
Congrats to both players. Not entering the last digit - so in my world it is a draw.
on 2. March 2025, 12:06 by Syzygy
Wonderful puzzle! Thank you for taking the time to create it.
I loved the combination of Tic-Tac-Toe logic with Sudoku, worked really well!
on 2. March 2025, 01:18 by larmoejr
Really enjoyed this puzzle. Thank you.
on 1. March 2025, 23:52 by brewring
Ooh, the drama, the suspense, the plot!! That's what I love the most in your puzzles, the climax is never given away until the very end. Congrats to the winner, I was rooting for him.
on 1. March 2025, 20:35 by wuc
Awesome. Maybe a reversi follow up? Great work. Keep the game series going. Thx a lot.
on 1. March 2025, 20:20 by npinguy
Delightful!
on 1. March 2025, 20:00 by mscha
Very, very nice!
I found it not too difficult, the fog guides you nicely over the board so you know what to work on.
I'm pretty sure this is the first time ever that I scored the difficulty a star lower than the average. Typically, I give it a star more than the average.
on 1. March 2025, 16:48 by Visumation
Very nice. Very cool idea and execution.
Probably 2 stars for me.
on 1. March 2025, 16:31 by Lorena
Absolutely amazing as usual, Marty.
on 1. March 2025, 16:01 by Nell Gwyn
It was an hono(u)r to solve this on the Twitch Train. Truly amazing.
on 1. March 2025, 15:55 by Franjo
Another amazing game-sudoku by the mastermind. Oh, maybe the next one will feature that old game? I really enjoyed solving this lovely puzzle! So nice that you even presented it with the original #-layout of the game. Thank you so much for creating and sharing.
Marty: Mastermind is a great idea! Adding it to my list ;)
on 1. March 2025, 15:10 by Snookerfan
Fun and clever puzzle with a great ending! Thank you
on 1. March 2025, 14:41 by Tinnifer
Wonderful puzzle as always Marty! I really enjoyed it.
on 1. March 2025, 13:18 by Asparagus
I loved the ending!
I wouldn't have expected anything less from you Marty!
Fantastic puzzle.
on 1. March 2025, 11:03 by sujoyku
Thank you for this fun puzzle, Marty! After the Connect 4, it is another perfect merge of game and sudoku logic. It gets harder after the break-in, but in the great manner of teaching you all the important little tricks along the way. Great puzzle!
on 1. March 2025, 09:17 by oskode
The double Tic-Tac-Toe logic was so sweet. Loved it, thank you!
