During a walker fight, target the closer ones first. The walkers will eventually shuffle closer to your survivors, but they will not attack until they are very close. When facing a swarm of walkers, target the ones that will come into contact with your characters first. When fighting other survivors, each enemy will be able to attack during its turn. When you find shorter obstacles, use them to block the walkers and force them to go around to reach your survivors. Using melee attacks against a walker behind an obstacle is ineffective. However survivors with guns can still hit walkers on the other side of barriers. Kill all the walkers except for one of them that is resistant to most of your survivors. When that walker gets near, attack it using the characters who do the least amount of damage. This will allow your weaker characters can build up their special attack. You can then start the next wave with those characters ready to use their special abilities. When fighting the hordes of walkers, attack and destroy the closest ones first, followed the ones in the back. The closer zombies will move in faster and attack first. Note: This will not work during Boss battles or human encounters, as they will all attack you.