How to play

The frame has seven columns and six rows. On your turn, tap a column and your disc falls to the lowest empty space in it. The first player to line up four discs in a row, across, down or diagonally, wins. If the frame fills up first, it is a draw. Red goes first; you can choose to go first or second against the computer, or pick 2 players and take turns on one screen. The yellow discs have a ring in the middle, so the two colors are easy to tell apart.

The computer has three levels. Easy wins or blocks when a line of four is one disc away, and otherwise plays at random. Medium looks four moves ahead. Hard looks seven moves ahead and scores the positions it sees, favoring the middle columns, so it is a real challenge.

Tips

The middle column is the most valuable one, because discs there are part of more possible lines. Try to build two threats at once, such as a row of three with open ends or two lines that need the same spot. Watch out for threats that sit one space above a gap: if the gap is empty, whoever fills it gives the other player the space above. In a long game, count out which player will be forced to play under the other’s threat.