A complete guide: the goal, taking turns on a 3×3 board, how to get three in a row, how a draw is read, controls on muta.pro and tips to stop losing as a beginner.
Tic-Tac-Toe is a fast duel on a board 3×3. One player places crosses (X), the other noughts (O). The task is to be the first to build three of your marks in a row horizontally, vertically or diagonally. Whoever does it first wins the game instantly. If the board is filled and no line has appeared, it is declared a draw.
A game lasts less than a minute, so people usually play in series: the tally of wins, losses and draws builds up until you close the room.
The board is a grid of nine empty squares. On muta.pro you are immediately given the crosses (X), and X always moves first. The opponent — a bot or a second player — plays noughts. Before starting, choose a mode: against a bot or two players in one room. After each game you can start a new one with the “New game” button, and reset the series score if you wish.
The first move always belongs to X. X may take any of the nine empty squares at will.
Players alternate: after X comes O, then X again. Exactly one mark is placed per move.
An X or O once placed stays in place until the game ends — it cannot be removed or moved, nor can an occupied square be taken again.
After every move the game looks for three identical marks in a row — along a row, a column or one of the two diagonals. As soon as a line is formed, the game ends immediately in a win.
If all nine squares are filled and no one has a line, it is a draw. A new game starts on a clean board.
Typical situations on a 3×3 board. X (you) are gold, O are blue. Key squares are highlighted.
A win — three of your marks on a single line: three horizontally, three vertically or three diagonally. On a 3×3 board there are eight such winning lines in total. The winning line is highlighted, and a win is added to the series score.
A draw occurs when the board is filled without a single line. With sound play by both sides, tic-tac-toe almost always ends in a draw — so the whole interest lies in catching the opponent off guard. The score is kept separately: X, O and draws.
The center square is part of four of the eight lines. If you move first, take it — it is the strongest start.
Build your position so as to threaten two lines at once. The opponent blocks one — you complete the other.
Before your attacking move, check whether the opponent has two marks in a row. If so — block the line first.
Corner squares belong to three lines, side squares to only two. All else being equal, prefer the corners.
Strength in tic-tac-toe lies not in calculating ten moves ahead, but in instantly scanning the eight lines before every move. An experienced player doesn't "think" — they check the board along a fixed route and find every threat at a glance. Below is exactly that route, worth drilling until it's automatic.
Is there a line with two of your marks and an empty third cell? Play there and win. This step always comes first — otherwise you might "defend" in an already-won game.
Two of the opponent's marks on an open line — block the third cell immediately. A missed block cancels the whole game, so this step is mandatory before any plans of your own.
A line with one of your marks and two empty cells is the setup for a future threat. Cells lying in two such setups at once are candidates for a fork.
The center is part of 4 lines, a corner of 3, an edge of 2. While scanning the board, give priority to cells with a greater number of lines: that's where double threats are born.
Top line — two crosses and an empty cell on the right: scanning immediately highlights it as a ready three.
Crosses always play moves 1, 3, 5, 7, 9, and noughts — 2, 4, 6, 8. From this follows the main practical endgame rule: if your three completes earlier than the opponent's by the move count — don't defend, strike. Whoever completes the line first wins; a needless block in that situation simply loses tempo.
Check the race literally by move numbers. Your threat matures on your nearest move, the opponent's on theirs. If your move comes first — the opponent doesn't make it in time.
Crosses to move: their own three up top completes right now, while the opponent's pair below only on the next move. Strike, don't defend.
Your threat on move N, the opponent's on N+1 — you're faster. Don't spend tempo blocking something that won't fire in time.
A ready three of your own is stronger than any setup of the opponent's: complete the line rather than dismantling threats that are too late anyway.
Crosses move on odd numbers and in a "two against two" race are usually half a tempo ahead — use this first-move advantage.
Classic 3×3, with precise play, is always a draw, which is why the game has grown many variants where calculation and planning now decide. Knowing them is useful: the same fork and tempo techniques work there too, just with more lines and cells.
The goal flips: whoever makes three in a row loses. All the usual tactics are mirrored — now you avoid threes and push the opponent toward a forced line.
The board grows to 15×15, and victory requires five marks in a row. The fork idea stays the core of strategy, but "open threes" and double threats of a far higher order appear.
Nine small boards inside a big one: your move determines on which board the opponent plays. A local win takes a cell of the big board — the depth of calculation grows sharply.
On a 4×4 board with the "three in a row" goal, the first player wins by force. It's good practice for building forks without the 3×3 draw ceiling.
A 4×4 board, goal "three in a row": the top three crosses are completed by the free cell on the right — on a large board such lines multiply.
People lose at tic-tac-toe almost always not from ignorance of theory, but from errors of perception — the eye latches onto its own attack and doesn't see the whole board. Let's break down the typical thinking failures and a simple antidote to each.
The 1-5-9 diagonal of three crosses — the line the eye notices last; scan both diagonals separately.
"My three? The opponent's three? Diagonals?" — three questions before every move remove almost all blunders.
Your own pretty line isn't worth a loss. Until the opponent's threats are closed, your plans can wait one move.
Don't poke at random into one of the two threats: your own "pair" forces the opponent to defend and wrecks his forking move.