SuperTac tips
7 tic-tac-toe mistakes that quietly lose you games
Most losses are not clever traps sprung by a genius opponent. They are the same handful of habits, repeated. Here are the seven that cost the most games, and the fix for each.
1. Only looking at rows and columns
Diagonals are the lines people miss, because the eye scans left-to-right and top-to-bottom. Make a rule for yourself: before every move, check both diagonals through the square you are about to play, and both diagonals your opponent is building.
2. Chasing your own line and ignoring theirs
It feels productive to extend your line every turn, but if your opponent completes theirs first, none of it counts. Check their winning square before you look at yours — every single turn.
3. Blocking the wrong end
When you block a three that is open at both ends, the two ends are rarely equal. Block the end that also sits on your opponent's other developing line, or the end that helps one of your own lines. A block that does double duty is worth two moves.
4. Forgetting that forks exist
You can block every single threat one at a time and still lose, because the losing move was three turns earlier when you let your opponent create two threats at once. If a square would give them two lines with two marks each, that square is urgent even though nothing looks dangerous yet.
5. Playing edges too early
On a 3×3 board, the edge squares belong to the fewest winning lines, and an edge opening is the only first move that can be punished outright. On bigger boards the same logic applies to the outer ring — start where more lines cross.
6. Spending the whole game defending
If you have blocked three turns in a row, you have handed over the game. Look for a move that blocks and threatens at the same time, or accept a small risk to force them to answer you instead.
7. Playing the same opening every time
Against a friend or a strong AI, repetition is readable. Vary your first move, and vary the settings too — change the board size or the number in a row you need and old habits stop working for both of you.
Quick takeaways
- Check their threats before your own.
- Scan diagonals deliberately.
- Choose the blocking square that also helps you.
- Stop forks before they exist, not after.
- Mix up openings and settings.