10) Use options in the IAP store to earn free gold.
You will be able to earn free gold via watching advertisement videos, connecting the game to Facebook, or completing offers on Tapjoy. Plus, if you go to Tapjoy.com and log in, and search for offers related to Empire Z, you’ll be able to earn even more free gold by completing those. Those are the offers that aren’t allowed to be shown within the app itself.
9) Upgrade to the High Stakes room in the casino.
If you purchase gold, you will be able to unlock the High Stakes room in the casino for even better rewards than you normally get from the casino. This is the only reward which cannot somehow be earned for free in the game, and you can do without it, but it’s a sweet luxury to have. It’s also possible to earn a High Stakes Room key from the gold bonuses earned by your alliance members.
8) Make sure that your storage bunker is upgraded to as high of a level as possible.
This will make it completely worthless for other players to attack you. You’ll be hard pressed to have enough resources to overflow the storage bunker, and your oil, food, metal and wood will all be protected. Only your coins will remain unprotected. For this reason, usually it is worthless to attack another player too, unless you simply want to maul their troops and their hero and force them to teleport away from their current location (good for clearing space for an entire alliance to move to).
7) Get your alliance together to focus on destroying one Infected City at a time.
Infected Cities are LOADED with zombies, and when you clear them, they will become deserted cities loaded with resources. This is another reason that an active alliance is important, because typically everybody will do a single-digit amount of damage to the zombie horde at a time. Plus, when the city is cleared, everybody who participated in the battle will get free gold, and the chance to capture a zombie leader.
6) Look around for other players who have abandoned their cities and/or deleted Empire Z.
It’s easy to find these players. They’re the ones with no troops (use recon to see how many troops they have, and upgrade recon in the research lab if it doesn’t tell you). These players, if they are undiscovered, may actually have enough resources to make an attack worth it, because their resources may have outgrown their storage bunkers.