4 in Line is a strategy board game that is over a century old. The game is simple to understand, but extremely difficult to play. It is played with a 7-column, 6-piece board. On each turn, players move a number of tokens equal to their score, and the player with the most tokens at the end of the game wins. The game ends when one player has no more moves.

To play the game, you need to connect four tokens in a row, either horizontally, vertically, or diagonally. Each token can be connected to other tokens of the same color, but can also be connected to a token of a different color.

There are different levels of difficulty. If you play against the phone, the difficulty level is 3, and if you play against another person, the difficulty level is 2.

There is an AI engine in the game that can play with you. The AI has 3 difficulty levels, and can be customized by the player.