오목

The game is played on a 15x15 grid (sometimes 19x19, the same as a Go board). The board starts empty. Black plays first and players use black and white stones.

Create an unbroken line of exactly five stones of your color (or five or more, depending on rules). If the board fills without a winner, the game is a draw.

Players alternate turns, placing one stone of their color on any empty intersection. Once placed, stones never move or get removed. The first player to create five consecutive stones in a line wins.

Control the center of the board - it provides the most opportunities for five in a row. Look for double threats (open threes or fours) that cannot be blocked in one move. An 'open four' (four in a row with both ends open) is an immediate win if unblocked.

Renju: Professional rules for Black to balance first-move advantage. Black cannot make double fours, double threes, or overlines. Standard: Any five or more in a row wins for both players. Opening rules: Swap or swap2 rules help balance the strong first-player advantage.