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.
Elemental strengths
Character types are better against some types while being weaker against others. There are four elemental colors. Tap an enemy during a battle and check their bottom bar to see if you have survivors that are better against them.
Leveling
Do not keep more than fifteen characters. Upgrade the rarest ones first, and try to max them out. Consider having all elements represented with high level characters to be ready for all types of opponents. Sacrifice one star and two star characters as upgrade materials. As you acquire better characters, use them to replace worse ones.
Moral choices
Choice that you make will have a different moral outcome and change how the game progresses. However no matter what choice you make, the game will continue and not have a bad outcome.
Rewards
Do not collect rewards until they are needed. They will remain available at the "Missions/Achievements" tab, safe from other players. Collect them for quick progress and for use as an always available resource as needed.
Rush attacks
Learn each of your active characters' rush attacks. Use them when they are most useful. When a final wave approaches, consider using rush attacks as soon as possible to take advantage of boosts that last more turns.
Special abilities
Each character has a special ability that will power up as they deal and take damage. Take note of which character has a particular ability and when it is best used.
Teams
You can have up to three teams active at once. Always try have at least two teams going, one with your best characters for raiding or defending from raiders; and a second team that can be customized for single player missions, with modifications made depending on enemies that will be encountered. Optimally, create a four-class team for use to raid or defend, and a team with class advantages for single player missions.
Various General Tips
Always aim for the zombies closest to you first.
Only use autoplay in battles against zombies, as AI can usually handle them properly.
You can have up to three teams active, and one of them should be crafted specifically and exclusively for defending.
When fighting the hordes of zombies, it’s best to try and attack/destroy the closest ones first, then the ones in the back: the closest zombies will move in fast.
You should aim at not having more than 15 characters at any given time, and always choose upgrading the rarest one first.
Don't claim rewards until you actually need them, as they can't be stolen from the missions/achievements tab. Store them there and claim them when there is a need.
Survivors have four different traits, and they are marked with different colors. Blue beats red, red beats green, green beats yellow, and yellow beats blue.
You can get free coins by going to the IAP menu and either watching ads or complete offers.