About Five in a Row
Five in a Row is known across East Asia as gomoku and has been played for centuries on the same boards used for Go. It looks like a bigger noughts and crosses. It plays like a much sharper game.
How a match works
The board is eleven squares by eleven. One player places circles, the other crosses. On your turn, tap any empty square. A line of five in any direction wins at once, and the winning pieces are outlined. If the board fills with no line of five, the game is drawn, though that almost never happens.
The key shapes
Everything in this game comes down to threats.
A four is four in a row with an empty square at one end. Your opponent must block it immediately or lose.
An open four has empty squares at both ends. It cannot be stopped, because blocking one end leaves the other.
An open three is three in a row with space at both ends. Left alone, it becomes an open four on the next move. So an open three must be answered straight away as well.
How to win
Make two threats at once. A single open three will be blocked. But if one move creates two open threes, or a three and a four together, your opponent can only stop one of them. Setting up that double is the whole aim of the attack.
Build diagonally as well as straight. Lines that cross at an empty square are how doubles are made.
Block early. Stop an opponent's three before it becomes a four, and block on the side that also helps your own position.
Keep the initiative. As long as you are making threats that must be answered, your opponent has no time to build.
Play near the centre, where lines have room to grow in every direction.
Of all the board-style two-player HTML5 games, this has the best ratio of simple rules to real depth.