Four in a Row is a two-player game on an upright grid of seven columns and six rows. Players take turns dropping a disc into a column, where it falls to the lowest empty cell. The first to line up four of their own discs — across, up and down, or on a diagonal — wins. If the grid fills up first, it is a draw. On this page you play against the computer; in every Toque set the board puzzle is a position taken from this game, with a forced win waiting to be found.
How to play
- Tap a column, or the space above it, to drop your disc. With a keyboard, move along the columns with the arrow keys and press Enter.
- Dark moves first in a new game. You can choose your colour, the computer's level from Beginner to Master, or a two-player game on one device.
- The game marks the last move, possible moves and the winning line. Undo takes back your last move together with the computer's reply.
Strategy
- Start in the middle. The centre column takes part in more possible lines than any other, so early discs there are worth the most.
- Make threats, not just blocks. A threat is an empty cell that would complete four for you. Each one restricts where the opponent may play.
- Two threats at once win. The opponent can only block one. Most of the board problems on Toque end with exactly such a double threat.
- Watch the cell below a threat. A threat can only be used when the cell beneath it is filled. Playing into the cell under your opponent's threat hands them the win.
- Stacked threats are decisive. Two of your threats directly above each other mean the opponent cannot block both in time.
The board problems in each set
Each set contains one position where it is your move and you can force a win within two, three or four of your own moves. The opponent defends as stubbornly as possible. Any move that keeps the forced win is accepted; a move that lets the win slip is marked "not the strongest move" and taken back, so you can try again. Every position was proved by an exhaustive search: exactly one first move works.
Questions
How strong is the computer?
Beginner misses simple tactics on purpose; Casual looks a few moves ahead; Strong searches deeper; Master searches for most of a second per move and, later in the game, switches to an exact solver.
Is the game solved?
Yes — with perfect play the first player wins by starting in the centre. That takes a great deal of memory, though, and the computer here does not use an opening book.
Why was my move in the problem taken back?
Because after it the win could no longer be forced. The problem asks for the strongest move each time, not just a reasonable one.
Can I play with a friend?
Yes. Choose a two-player game in the new-game menu and pass the device between turns.