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