How to play Four in a Row

Four in a Row is a game of falling discs. Two players take turns dropping a disc into one of seven columns of an upright grid; the disc slides down to the lowest free space in that column. The first player to line up four of their own discs, across, up or along a diagonal, wins.

The rules take seconds to learn, but the game runs deep. Because discs stack up from the bottom, you can only ever play the lowest free square of each column, and that turns the game into a battle over timing: a threat you build now may only become playable many moves later, and whoever is forced to give way first often loses. There is no luck at all; everything is on the board.

How to play on skill.games

In the settings popup choose a difficulty (Easy, Normal, Hard or Crazy) and press PLAY. The board has 7 columns and 6 rows. You play the red discs and you always move first; the computer plays the yellow discs.

• Dropping a disc: tap anywhere in a column. You can also press and slide: your disc hovers above the board over the column under your finger, a white ring shows where it would land, and lifting your finger drops it.
• Full columns cannot be played; a tap on one is refused with a little shake.
• The latest disc carries a small white dot, so you can always see where the computer just played.
• Score line: the top of the screen shows how many discs each side has dropped and whose turn it is.
• Easy only: a red ring warns you of any square where the computer's next disc would make four.

The menu button in the top-left corner pauses the game and lets you resume, start a new game or switch the sound on or off. The game is saved at every turn, so an unfinished game can be picked up later with CONTINUE.

When someone makes four in a row, the winning discs are ringed and joined by a line, then the results screen shows the outcome, the length of the line and the number of moves, together with your statistics for that difficulty: wins, losses, draws, win rate, current streak and best streak.

Rules

• The grid starts empty. You drop first, then you and the computer take turns.
• On your turn you drop one disc into any column that is not full. It falls to the lowest empty square of that column.
• Four or more of your discs in a straight line wins: horizontally, vertically or diagonally.
• Discs are never moved or removed once dropped.
• If all 42 squares fill up and nobody has four in a row, the game is a draw.

Strategy tips

• Play the middle. The centre column is part of more possible lines than any other, and the columns next to it come second. Discs on the edge columns can join only a few lines.
• Stop open threes at once. Three in a row with an empty playable square at either end must be blocked immediately. Three with both ends open on the bottom row usually cannot be stopped at all.
• Make two threats. As in most line games, the winning blow is a move that creates two different fours-in-waiting. Your opponent can block only one.
• Watch the square above. Before you drop a disc, look at the square it creates on top of it. If the computer wins by playing there, your move hands it the game.
• Use the odd and even rows. Count rows from 1 at the bottom. As the player who moves first, threats whose empty square is on an odd row (1, 3, 5) tend to work in your favour near the end of the game, when the columns fill up and someone is forced to play underneath a threat. Threats on even rows suit the second player.
• Build threats that wait. A threat that cannot be played yet is not wasted: it controls a whole column, because neither player wants to be the one who fills the square beneath it.
• Think about the end. When only a few columns are left, count how the remaining squares will be shared out. Being forced to move is often what decides the game.

Difficulty levels

• Easy: looks only at its next disc, misses about a third of your threats and drops about a third of its discs at random. It always takes a win when it sees one.
• Normal: always blocks a four you could make next turn and looks a few discs ahead, but now and then drops a disc at random.
• Hard: looks eight discs ahead and never plays at random. It sets traps and avoids most of yours.
• Crazy: searches as deep as it can and, from the middle of the game on, usually works out the result exactly. It almost never makes a mistake: moving first is your best chance against it.