Strategy

Outbreak is simple but deep.  You can become competent quickly but it will take some time to master.

At the beginning of the game, move towards the center of the board in order to take up a maximum amount of space. If you remain confined to the corner you start in, you will not be able to put down many cells.

Try to place the largest cells on the board at the beginning of the game. If you save them for the end of the game, there may not be space for them. Keep an eye on the corners of your cells - make sure you have options for your next move.

Take advantage of the characteristics of your cells. Their shapes give them different offensive or defensive potential, so learn to use them accordingly.

Be tactical. Blockade your opponents while expanding your own territory! You can block your opponent by covering his or her most advanced corners to prevent her from moving forward. Be patient though, it is sometimes better to hang back slightly from the opponent's cells and let your opponent expose herself so that you can then block her more effectively.

Take note of the spaces where no other player can play and keep these spaces (and their corresponding cells) in reserve while you play in a more exposed area. You can always come back to the protected spaces later.

When playing, keep in mind not only your remaining cells, but also your opponent's remaining cells. Your opponent may not be able to exploit an empty area if she doesn't have the correct cells.

Learn to notice which of your corners are still alive, with potential to accept placement of another cell.

Watch for opportunities to escape to another area of the board.  Because cells are only placed corner to corner for each player, it isn't easy to completely block a path.  Careful planning can let you cut right through the line of another player.

Remember: Players who put all their cells on the board can gain bonus points. Prevent your opponent from putting all of her cells on the board even if this prevents you from placing some of your own cells on the board.

Good luck!