Dots and boxes

Dots and boxes brings the classic pencil-and-paper duel online exactly as most people learned it as kids: take turns drawing one line between two dots, and whoever completes the fourth side of a box claims it and gets to go again. That extra-turn rule is what gives the game its real strategy — completing a box now can hand your opponent a free chain of boxes to claim right after, so strong players spend most of the game avoiding the third side of any box rather than rushing to finish them. Reading the board ahead to see which lines are actually safe to draw, especially in the mid-to-late game, is what separates a close match from a rout. It's a fast, replayable two-player game that's free to play directly in the browser, no download or account required to start a duel.