'Tic-tac-toe' or 'cross & noughts'

Let the no. in each block represent the location of a mark. Then, from rule 3, the seventh mark must be placed in block 5. And from rule 2, the seventh mark wins for both X and O.

Since lines 1-4-7 and 7-8-9 have 2 opponent marks, this tells us that the 6th mark must either be in block 7 or block 9. However, placing the 6th mark in block 7 would contradict rule 3c, where O would rather play it in block 5 and win the game. Thus, the sixth mark was placed in block 9 and it was 'X'.

Accordingly, the 7th or the final mark must be 'O' and $\boxed {O}$ wins the game.

Assume one of the players goes first. Try to reason through all options and imagine a real-life situation where you and your friend are playing a game. Since this is supposed to be a logic puzzle, think about the possibilities of what he would do. Though there are many possible game like 1,8,4,7,9,2. 2,1,4,7,8,9 , using the rules given, it would be O winning the game.

The last move concludes the game; which directly depicts it's O's move in the middle cause O follows all three rules and X does not.

Whoever played first, they still have a threat on board, so their opponent's 3rd move needs to have been made to prevent another threat. Supposing X played first, O's 3rd move must have been in the lower-left corner, but this would mean that O already had a threat on board, which X should've countered, according to rule (b). Or which O should've preferred, according to rule (c). So X couldn't have played first to reach this state, according to the stated rules.

Therefore, O played first (and will thus win on the next move), and their 3rd move must've been to the middle of the bottom row. X chose to counter in the corner instead of in the center. The previous moves could've happened in any of the 4 possible ways.