Play Tic Tac Toe against the computer.

Why the computer never loses

Tic-tac-toe is small enough that a computer can look all the way to the end of every possible game before making a single move — a technique called minimax, where the AI assumes you'll always play your best response and picks whichever move guarantees the best outcome even against that. That's the entire trick: it isn't reacting to you, it already knows how every line of play ends.

With perfect play from both sides, tic-tac-toe always ends in a draw — a fact mathematicians settled with certainty a long time ago, since the whole game tree is small enough to check completely. That's why forcing a draw against this computer, rather than expecting a win, is genuinely the correct goal.

For your own game against less perfect opponents, take the center first if it's open, then a corner over an edge — center and corners each sit on more possible winning lines than an edge does, which is the actual reason that opening advice holds up.