The game progress requires a number of resources to be collected, and also provides these resources in a manner to limit unbalanced progress. As the game progress the resource requirements are exponetially increased. At the same time, the rewards are not equally increasing in value, to make the game more challenging. If the resource gathering becomes too challenging and repetitive there may be players quitting.
The term farming is often used about gathering resources at easy missions with a known and abundant outcome, as a referenece to how a farmer with some work can harvest crop. "The Pay Wall" is a term used to describe the level at which players feel the need to use real money, as opposed to in-game resources, to pay for advancing the game.
Primary Resources[]
All primary resources can be generated by a building or rewarded after missions.
Supplies[]
The Supplies are represented by tin cans and are thus also known as food or tomato soup.
Supplies are needed to create and upgrade Buildings.
Supplies are mainly stored in the Supplies Storage buildings that needs to be upgraded to not become saturated.
XP[]
Experience Points, known as XP, are represented by sheriff badges.
XP grows when killing Walkers. Can also be rewarded from loot chests. The Tents produces minor amounts of XP per hour if collected.
XP are needed to upgrade Survivors or Equipment.
XP are stored mainly in the Council that needs to be upgraded to not become saturated.
Gas[]
Gas is needed to fuel the missions. Gas magically generates at a steady state of 1 unit per 10 minutes.
The gas is stored in the Mission Car that needs to be upgraded to not become saturated.
Gold[]
Gold is represented by gold bars. This is often not an essential resource, but can be used to cover for other supplies.
Gold needs no separate storage and seems to be an unsaturated resource.
See separate page on Gold.
Secondary Resources[]
Secondary resources cannot be farmed, but is produced by the use of primary resources.
BP[]
Building points, known as BP, are generated when you construct or upgrade buildings. BP is the underlying resource for Player Level and that is also the only representation.
Player Level[]
Player Level is not really a resource, even though a certain count may be required to advance the game. See separate Player Level section for details.
Other[]
Paying real money in the Shop can fill up resources or advance the game in other ways. Sometimes watching video ads is another way for it.
Equipment and Survivors are definitely resourcefully used to advance the game. They are in general however not considered as basic resources, even though they can to some extent be given as rewards during the game or retired/scrapped with a resource refund.