Rules of Four in a Row
Four in a Row is played on an upright grid of 7 columns and 6 rows (42 cells). Two players, Coral and Mint, take turns choosing a column and dropping one disc into it.
Gravity does the rest: the disc falls straight down and settles in the lowest empty cell of that column. A column that already holds six discs is full, and nobody may drop into it again.
Horizontal
Four discs side by side in one row.
Vertical
Four discs stacked on top of each other in one column.
Diagonal
Four discs climbing like a staircase, either up to the right (/) or up to the left (\).
- The first player to line up four of their own discs in an unbroken line wins at once.
- Lines of five or more also count; every disc in the line is highlighted.
- If all 42 cells are filled and nobody has four in a row, the game is a draw.
- In online games each move must be made within 15 seconds, or the clock decides the game.
Winning strategies and the mathematics behind them
The 7x6 game has been solved by computer: with perfect play the first player wins, but only by opening in the centre. These three rules capture most of what that analysis teaches.
Rule #1: Control the centre column
Label the columns A to G. Every horizontal four must cover four neighbouring columns, and on a seven-column board each of the four possible spans (A to D, B to E, C to F, D to G) includes column D. The same is true of every diagonal. The centre column therefore takes part in more winning lines than any other column.
Open in column D, keep adding discs there when it is safe, and treat columns C and E as the next most valuable. A disc on the edge (A or G) can join only a handful of lines.
Rule #2: Build the 7-trap
A single threat (three in a row with an empty fourth cell) can simply be blocked. A double threat cannot. The classic way to make one is the "7" shape: a horizontal three along the top bar and a diagonal three running down the stem, sharing a corner disc.
The strongest version puts the two empty winning cells directly on top of each other in the same column. When your opponent blocks the lower one, they place a disc under your upper threat and hand you the win.
- Look for squares where your horizontal and diagonal lines cross.
- Never fill the cell directly beneath an enemy threat unless you are forced to.
Rule #3: Odd and even rows, and zugzwang
Count the rows from the bottom. As the board fills up, the first player naturally ends up filling the odd rows (1, 3, 5) and the second player the even rows (2, 4, 6). That makes a threat on an odd row a long-term asset for the first player, and a threat on an even row an asset for the second player.
In the endgame this turns into zugzwang: when every safe move is used up, the player who is out of good moves must drop a disc that lets the opponent complete a line. Plan your threats on the right parity and you can win without ever making a direct attack.
Pop-Out mode guide
Pop-Out is an optional variant available against the AI and in private rooms. On your turn you may either drop a disc as usual, or pull one of your own discs out of the bottom row. Every disc above it in that column then drops down by one row.
Because a pop shifts a whole column, it can create lines for both players at once. If that happens, the player who made the pop wins. If the pop only completes a line for the opponent, the opponent wins, so look carefully before you pull.
- A full board is not a draw in Pop-Out: play continues as long as the player to move can pop.
- If the same position appears three times, or the game runs very long, it is declared a draw.
- Popping is a powerful defence: removing a bottom disc can break an enemy threat higher up.
Frequently asked questions
Is Four in a Row Online free?
Yes. Every mode is free and runs in your browser. There is nothing to install and no account to create.
Does the first player have an advantage?
Yes. The standard 7x6 game was mathematically solved in 1988: with perfect play the first player wins by opening in the centre column. Against human opponents both sides still have plenty of chances.
How does Online Quick Match work?
Tap Online Quick Match and you join a queue of waiting players. When someone else is looking for a game you are paired instantly. If you would rather not wait, press Start Immediately with AI to play the computer right away.
How do I play with a friend?
Choose Play with a Friend, pick Classic or Pop-Out rules and create an invite link. Send the link to your friend; the game starts as soon as they open it. Rematches alternate who goes first and the score is kept for the whole session.
How strong is the Grandmaster AI?
Grandmaster searches nine moves ahead or more with alpha-beta pruning and a transposition table, and it recognises double threats and odd/even row control. It runs inside your browser and usually replies in well under a second.
What is Pop-Out mode?
A variant where, instead of dropping a disc, you may remove one of your own discs from the bottom row so the column slides down. It is available against the AI and in private rooms.
How long do I have for each move online?
Fifteen seconds. If the clock runs out, the opponent wins that game. Games against the AI and Pass & Play games have no clock.
Can I play on a phone, and with colour-blindness?
Yes. The board adapts to any screen and works with touch, mouse or keyboard (arrow keys and 1 to 7). Discs carry a star or a diamond symbol, so you never have to rely on colour alone.