Tic-tac-toe strategy and how to play Vanishing XOX
Everyone knows tic-tac-toe: get three in a row across, down or diagonally. The catch is that two careful players always draw. This guide covers the classic strategy that never loses, then dives deep into Vanishing XOX, our twist where old marks disappear and the game stays alive.
How to play classic tic-tac-toe
The board is a 3x3 grid. One player is X, the other O, and you take turns marking an empty square.
First to get three in a horizontal, vertical or diagonal line wins. There are 8 winning lines in total: 3 rows, 3 columns and 2 diagonals. If all nine squares fill up with no line, it is a draw.
Tic-tac-toe strategy: how not to lose
- Squares are not equal. The center is on 4 lines, each corner on 3, each edge on only 2. Center beats corner beats edge.
- Going first, open in a corner. Your opponent’s only safe reply is the center; anything else lets you force a win.
- Make forks: a move that creates two separate threats at once wins, because they can only block one.
- Going second, answer a corner opening with the center, and a center opening with a corner.
- The classic trap: X takes a corner, you take the center, X takes the opposite corner. Do not take a corner now. Play an edge; a corner lets X fork.
- Before every move, check in order: can I win, must I block, can I fork?
Why does tic-tac-toe always end in a draw?
Tic-tac-toe is a solved game. With perfect play from both sides it is always a draw, no matter who starts.
Most people reach that level after a few dozen games, and then the fun drains out. Vanishing XOX exists to fix exactly that.
Vanishing XOX rules
- Before you start, pick a board: 9 squares (3x3) or 12 squares (3 columns, 4 rows).
- Take turns placing your mark on an empty square.
- Each player can have at most 3 marks on the board. The moment you place a 4th, your oldest mark vanishes.
- Your shaking mark is the one that disappears on your next move. Your opponent’s shaking mark goes on their next move.
- You cannot place on a taken square, and the square of your own about-to-vanish mark still counts as taken.
- If your three marks form a line after the new one goes down and the oldest leaves, you win.
- If nobody makes a line in 30 total moves on 9 squares, or 40 on 12 squares, it is a draw.
How vanishing works, move by move
- Your first three marks build up just like normal tic-tac-toe.
- After your third mark, your first one starts shaking: it leaves on your next move.
- You place your fourth mark on an empty square, and your shaking mark is wiped at the same moment.
- The game checks your three remaining marks, your two newest plus the one you just placed. In a line? You win.
- If not, it is your opponent’s turn, and your second mark is now the one shaking.
Can Vanishing XOX end in a draw?
The board never fills up. On 9 squares there are at most 6 marks, so there is always an empty square to play. A draw only happens when the move limit runs out.
Stockboi’s computer has worked out every position of 9-square Vanishing XOX. The result is a surprise: if the first player opens on an edge square and plays perfectly, they can force a win within 13 moves in total, on their own 7th mark. Open in a corner or the center and neither side can force a win.
So the square that is weakest in classic tic-tac-toe becomes the strongest opening here. Pulling off the full sequence without a slip is hard, which is why most games end early on someone’s mistake.
Vanishing XOX strategy
- A winning line is always your two newest marks plus the one you place. Your shaking mark leaves on your next move, so do not count on it.
- Read threats correctly: a pair made of your opponent’s two newest marks with an open third square is real. A pair that includes their shaking mark is not.
- Blocks expire: every mark you place disappears on your third move after it. When you plug a key square, know when that plug will pop.
- Plan for freed squares: your opponent’s shaking mark leaves a gap after their next move. Build your plan around it.
- Play with tempo: threats that force a block every turn keep their marks on defense, so they never get to build.
- Opening on 9 squares: the edge is the theoretical winning start; corners and the center are steadier but do not force anything.
- On 12 squares: the two middle squares of the center column sit on 5 of the 14 lines, corners on only 3. Whoever holds the middle makes more threats.
Common mistakes
- Completing three in a row and forgetting your oldest mark vanishes at that exact moment, breaking the line.
- Wasting moves blocking a pair that contains a shaking mark.
- Trying to place on your own shaking mark’s square; it still counts as taken.
- Assuming a line you blocked stays blocked forever.
- Focusing on your own plan and missing the square your opponent is about to free up.
A short history of tic-tac-toe
Three-in-a-row games are very old and played on paper all over the world. In Britain it is noughts and crosses; in Turkey it is XOX.
Tic-tac-toe also matters in computing history: OXO, written in 1952 for the EDSAC computer at Cambridge, is counted among the first video games with a display. Games where each side has only three pieces that keep moving have existed for centuries too; Vanishing XOX is our take on that idea.
Playing tic-tac-toe on Stockboi
Play in your browser, no sign-up, no download. Solo, you face the computer on Easy, Medium or Hard. Easy mostly plays at random, Medium never misses a ready win, and Hard has the whole 9-square game solved.
Online, create a room and send the link to a friend, or get matched with a random opponent who picked the same board. Whoever creates the room picks the board. You get 60 seconds per move, and the first move switches sides every round.
On a phone, just tap an empty square. On a keyboard, keys 1 to 9 pick squares on the 9-square board.
Frequently asked questions
What is the best first move in tic-tac-toe?
In classic tic-tac-toe a corner is best, since it gives your opponent the most ways to go wrong. In 9-square Vanishing XOX, an edge opening followed by perfect play forces a win.
Is there a way to always win tic-tac-toe?
Not in the classic game; perfect play on both sides is always a draw. In 9-square Vanishing XOX the first player has a forced win, but it takes a long run of exact moves.
Which mark disappears in Vanishing XOX?
Always your own oldest mark, the moment you place your 4th. It starts shaking one move earlier so you can see it coming.
Can Vanishing XOX end in a draw?
Only on the move limit: 30 moves on 9 squares, 40 on 12 squares. The board itself never fills up.
Can I play on the square of my shaking mark?
No. That square still counts as taken until the mark is actually gone.
What is a fork in tic-tac-toe?
A move that creates two winning threats on different lines at once. Your opponent can block only one, so a fork usually wins the game.
What does the 12-square board look like?
It is 3 columns by 4 rows, made to fit a phone held upright. It has 14 winning lines and a 40-move limit.