Hmmm redstone tick tac to should be doable.
I started out with the display for a scoreboard, but the wireing of the display itself is allready a struggle, not even talking about the space the logic will take up.
Just 2 panels with 9 switches.
and a 3x3 pannel with O and X in them, and a little logic that only 1 can be selected.
Maybe with flipflops (memory) so the input is saved until the hole bord is reset.
18 flipflops, 36 and ports with 1 inverted input to check if the field is free.
I'll abandon the scoreboard, as a game in a game is more fun to build, maybe even worthy a warp

And when done, i can add the scoreboard after the game. And a check of somebody wins

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The win logic will be a pain killer.
There are 8 win conditions for each team.
Those can be read from the flipflops, but needs AND 2 checks a condition. for 2 players, thats 32 AND ports.
Then we need 7 OR ports, for the 8 conditions (1 of the conditions is a win), so 14 more ports.
And them some little logic that prefents them from playing once someobody has one.
And ist still smaler then a simple 8 bit counter. i think.
But again, to wire the display would be the hard stuff as the paths redstone needs to take are getting close to eachother.
Maybe with 1x space between the torches it will be easy'r done.
3x3 a 'sign' (X or O) is needed. with a whitespace it would take up 5x5.
With 2 space between the 'sign', the screen would be.... 23x23 Still nothing compaired to the logic needed

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Yeah, i got it in my head how i want to make this tic - tac - to. So this will be done!
Steps to take:
1: Clear room (allready has some, but i clearly need more.
2: Make display (23x23) hope it fits, i'll make a single sign first (5x5).
3: Add 2x 9 switchboards (3x3) for O and one for X.
4: Make game work without logic and flipflops.
5: Then add flipflops & anti-cheat & reset.
6: Add win conditions.
And and have fun while playing/building this.