Rules
According to Blokus’s official website, players try to lay as many of their 21 pieces on the board before being blocked. Pieces resemble Tetris-like shapes, says Casual Game Play, and consist of one to five connected squares. Lay your first piece in the corner of the grid. Connect each additional piece diagonally to one of your other pieces. The game ends when no player can make any more moves. Points are awarded based on how many of your squares are on the board. You can win 15 bonus points if you placed all 21 pieces on the board, and five extra points if you placed your single-square piece last.
The Start
The Blokus official website recommends playing your largest pieces first and expanding your chain to the center quickly. It is harder to fit larger pieces near the end of the game. By expanding to the center you reduce the risk of being blocked in by other players,can and you are able to take up more space. However, Casual Game Play says that expanding to the center is not necessarily the only offensive play, because other players can cross your defensive chains wherever they are. It recommends laying your pieces in a way that will allow you to connect as many of your pieces as possible.
Piece Manipulations
Flip and rotate pieces to identify empty spaces on the board that one of your pieces may be able to fit into. This is extremely important to remember when playing the online version, as it is often more difficult to concretely visualize your pieces. Online, flip or rotate pieces with your mouse or space bar.
Single-Square Piece
Save your smallest piece (the single square) for near the end of the game. Not only because you can win five bonus points if it is used last, but you can place it almost anywhere, and it may allow you to start forming chains in a new portion of the board.
Opponent Chains
Look for chances to cross over the defensive lines of other players’ pieces. You may be able to flip or rotate a piece so that it connects to one of your pieces and squeezes through to the other side of another color’s chains.
Patience
The Blokus website advises that if there is an area of the board where it looks like only your pieces will fit, save this till near the end of the game. The website also suggests waiting for another player to play an offensive move, so that you can lay down a more effective counter-attack, blocking his pieces and expanding into his quadrant.
Keen Observation
As the game progresses, do not only look at your pieces but also at those of your opponents. This way you can anticipate his future moves and build a strategy to win the game.