How to Win at Tic Tac Toe

Naughts and crosses is essentially a child's game. It is simple to understand, simple to play and simple to win. However, due to this simplicity, two opponents with equal skill or strategy will always end up in a tie. A game played by two players of the same level must become a "Cat's Game", a common form of tying where both players followed the rules but still tied. There are 26830 unique games possible in tic-tac-toe, which seems to be an intimidating number, but is much smaller than that of checkers, chess and most other board or card games. Thankfully, only a few people are "perfect players", so I will help you by giving you THE strategy to win. Always.

THE BASICS:
There is a heirarcy of positions to move in in the game: the center, which is incorrectly the most popular due to its many borders and singularity; the corners, four of the most useful positions whose values are lost to most; and the sides, who are practically useless for precisely the same reason as the center is considered valuable. The real heirarchy for the usefulness of the areas is
1) the corners,
2) the center, and THEN
3) the sides.
The easy, lazy version of the following strategy is to one-up your opponent's last move. If you want to win, don't tie it, but instead surpass it (if possible). This means that when they go center, go to a corner. When they go corner, well, you can't pass that and shouldn't tie it, so go center. If they go side, laugh at them and go corner. If all the corners are full, go center; if the corners AND the center are all full, go side. However, if you get to the point where you HAVE to go side, odds are that the game will be a tie.

THE BEGINNING
Tic tac toe is a short game, but it is easily categorized into two parts: the Beginning, consisting of each player's first move, and the Gameplay, which is the rest of the game. You cannot really mark down a third part, as the end of the game might be two turns or eight turns into the Gameplay, depending on the level of the players.

Although it is the most popular move, there is only a one-half chance of winning if you play center to start the game. If your opponent plays perpendicular to you, on a side, then you'll easily win by putting your second move in a corner opposite of their piece and blocking it out. If they make their move in one of the corners, then the game will be a tie. Since any opponent with reasonable skill or talent will automatically counter diagonal, playing center is amateurish and risky.

If your opponent starts center, play diagonal. It will be a tie; oh well.

Your best bet for starting would be to start in a corner. This gives the fewest possible safe moves for your opponent. You will practically always win unless your opponent plays center. This almost always turns into a tie. Still, that leaves a lot of tempting open space for your not-as-skilled opponent, so the amateurs will usually grab at the wrong spot. Strike hard, quickly.

If your opponent starts in a corner, move center. That's your best bet at not losing.

That leaves one category of starting space open: the dreaded side. Do I start on a side, you ask? No. That's a stupid move, and will always end in a tie. The sides are the last resort for any part of the game. And if your opponent is dumb enough to play that, sit back and laugh. The game is yours, unless you do something absolutely idiotic.

Either way, after each player has done their first move, the best way to play it out is to perform the first possible move on the following list:

1) Win: If the player has two in a row, he or she can place a third to get three in a row.
2) Block: If the [opponent] has two in a row, the player must play the third himself or herself to block them.
3) Fork: Creation of an opportunity where the player has two threats to win (two non-blocked lines of 2).
4) Blocking an opponent's fork:
Option 1: The player should create two in a row to force the opponent into defending, as long as it doesn't result in them creating a fork or winning. For example, if "X" has a corner, "O" has the center, and "X" has the opposite corner as well, "O" must not play a corner in order to win. (Playing a corner in this scenario creates a fork for "X" to win.)
Option 2: If there is a configuration where the opponent can fork, the player should block that fork.
5) Center: A player marks the center. (If it is the first move of the game, playing on a corner gives "O" more opportunities to make a mistake and may therefore be the better choice; however, it makes no difference between perfect players.)
6) Opposite corner: If the opponent is in the corner, the player plays the opposite corner.
7) Empty corner: The player plays in a corner square.
8) Empty side: The player plays in a middle square on any of the 4 sides.