Play Four in a Row Online vs AI

Your turn.Discs0/0

How to Play Four in a Row

Play Four in a Row online on a 7×6 gravity board: red drops first, players choose a column, and the first to connect four matching discs horizontally, vertically, or diagonally wins. Start against multiple AI levels on this page with hints, undo, and replay, or switch to same-device play or an online room for a game with a friend.

How Four in a Row Works

The board has seven columns and six rows. Each turn, a disc drops into one column and falls to the lowest open slot. Red always starts; blue follows. The first player to line up four discs of their color horizontally, vertically, or diagonally wins.

A full column cannot take another disc. If all forty-two slots are filled and nobody has four, the game is a draw. Discs never move once they land, so every column height is part of the next decision.

A 7×6 Four in a Row opening with red and blue discs stacking from the bottom

Columns Set the Height

After you tap a column, the disc always occupies the lowest empty slot. It cannot hover or skip over discs already there. You are rarely claiming a particular cell; you are deciding which height that column will offer next. The center column runs through the most four-in-a-line windows, so it is often contested early. But if a threat of four is already on the board, blocking that column comes first.

7×6 gridGravity dropCenter column

A Four in a Row position where one drop creates two threats of four

Make Two Threats

If your opponent can complete four on the next drop, you must block that column. If you can complete four yourself, take it. The hard case is a double threat: one disc leaves two independent winning columns, and the opponent can cover only one. When you review a loss, the last missed four is usually already too late; look back for the move that let both threats appear together.

Take the winForced blockDouble threat

AI Play

The home page opens in AI mode. You can play red or blue and switch among multiple strength levels. A hint marks a candidate column; undo returns to the previous position so you can try another column; the move list and replay show which drop created a double threat. Search runs in the browser.

Multiple AI levelsHints and undoMove-by-move replay

7×6columns by rows

42slots on the board

4in a line to win

Redalways drops first