About Paint Battle
Paint Battle is a territory game played with colours. The board is a nine by nine patchwork of six colours. Each player owns a corner. Turn by turn, both territories spread across the board until they meet, and then the squeeze begins.
How a match works
Your territory is marked with your symbol, a circle or a cross. On your turn, tap one of the numbered colour buttons. Everything you own turns that colour, and any squares of that colour touching your territory join it. Those in turn may be touching more of the same colour, so one choice can add a whole cluster.
Two buttons are always greyed out: the colour you are now, and the colour your opponent is now. That stops either player from standing still or from invading the other directly.
The scores at the top count each player's squares. The game ends when one player holds more than half of the eighty-one squares, or when every square is taken.
How to win
Count before you choose. The obvious pick is the colour that adds most squares right now. It is often right, but look one move further.
Reach the middle first. The player who gets across the centre line confines the other to a smaller part of the board.
Use the blocking rule. Your opponent cannot choose the colour you are currently wearing. If they have a big patch of red sitting next to their territory, turning red yourself denies it to them for a turn, even if it gains you little.
Seal off regions. Once your territory forms a wall across the board, everything behind it will be yours eventually. You can then spend your moves on the contested border.
Do not strand colours. Leaving small pockets you cannot reach efficiently wastes turns at the end.
It is quick, colourful and full of small calculations, a good example of what turn-based HTML5 games do well.