Connect Four is a two-player connection game. The objective is to connect four of your colored discs in a straight line while preventing your opponent from doing the same.
The players take turns dropping one colored disc from the top into a vertically suspended grid. The discs fall straight down, occupying the lowest available space within the column.
The game ends when one player forms a horizontal, vertical, or diagonal line of four of their own discs. If the entire board fills up before either player achieves four in a row, then the game ends in a tie.
Four board sizes (6x7, 8x9, 9x9, and 10x10) are available in the BGA implementation.
Two optional opening rules are implemented to eliminate first player advantage.
- Pie rule: After the first player's first move, the second player may switch colors.
- Swap rule: The first player places three discs - a red disc, a yellow disc, and another red disc. After the first 3 discs are placed, the second player may switch colors.
The 6x7 board size is unavailable in Arena mode because the game is too easily solved.
The opening rule is locked as the swap rule, to allow various opening moves to be played and to remove any potential first/second player advantage.
Currently (since Oct. 2021), the board size option rotates as the season passes (9x9 → 8x9 → 9x9 → 8x9 → ...).
Gurus, do not vote for a 6x7 board size or non-swap openings!