The Maps in They Are Billions are quite small and full of zombies and villages of doom. Huge zombie swarms spawn at the edges from time to time and try to run your Command Center down. Currently there are 6 types of procedurally generated maps in the game, which are ordered in difficulty and need to be unlocked.
There are four unique map themes, each having their own weighted odds on world layout and resource values.
|Hunting Food Modifiers||Game Modifiers||Terrain Chances|
|The Deep Forest||15%||30%||60%||0-1 Doom Villages
? Treasure Piles
|The Dark Moorland||15%||30%||60%||1-2 Doom Villages
5-6 Treasure Piles
|The Peaceful Lowlands||10%||30%||50%||4-5 Doom Villages
4-5 Treasure Piles
|The Frozen Highlands||0%||40%||60%||1-2 Doom Villages
4-5 Treasure Piles
130% Building Energy
50% Zombie Awareness
80% Run Speed
|The Desolated Wasteland||0%||30%||60%||3 Doom Villages
7-10 Treasure Piles
150% Zombie Awareness
110% Unit and Zombie Watch Range
|Caustic Lands||15%||30%||60%||1 Giant Doom Village
5-6 Treasure Piles
The Deep Forest
The basic map, which is unlocked right from the beginning. Has no special infected on the map. Only the final waves spawns all special infected that are in the game, otherwise waves only spawn normal, fast and chubby infected.
The Dark Moorland
The basic map, which is unlocked right from the beginning. Not a lot of free space, many small water patches. Though the terrain impedes expansion, it is much easier to build defensive structures for the colony. The forest patches and small lakes reduces the number of walls needed to sufficiently defend the colony, making defence against waves early on much easier to deal with.
The Peaceful Lowlands
Requirements: Finish the Dark Moorlands with a score factor of at least 20% to unlock.
Has much more space than the Dark Moorlands, but the ground is only half grass, while the other half is made out of sand, on which you can't build farms.
The challenge lies in a tighter zombie population and more Villages of Doom, even right next to your starting location. The lack of natural structures like forests results in many more walls used to defend the colony, leading to a large investment of resources early on when defending the colony.
The Frozen Highlands
Requirements: Finish the Peaceful Lowlands with a score factor of at least 60% to unlock.
This map is built like the Dark Moorland in winter. The infected are less aggressive on this map, meaning that noise and death of other zombies will attract less attention.
The challenge lies in a higher energy usage and all units are slowed due to coldness.
Ranger move speed is 3.2 versus 4.0 in Dark Moorland, thus one may assume 20% reduction for all units.
The Desolated Wasteland
Requirements: Finish the Frozen Highlands with a score factor of at least 100% to unlock.
This map is a challenge map tuned to be about as hard as a map can be and still maybe be beatable. The Desolated Wasteland is a fairly open map with a large number of Villages of Doom, similar in some ways to the Peaceful Lowlands. However, unlike the Peaceful Lowlands, unbuildable terrain tends to be produced in numerous small clumps, and mesas are much more common than forests or water tiles. The narrow passages between these clumps mean that they provide little protection from wandering infected. Water terrain on the Desolated Wasteland is generated in such small patches that they often appear as simply cracks in the ground with no visible water tiles. Forest patches tend to be small, with forest tiles being represented as either Saguaro Cactus or Ponderosa Pine. Mesas are common, but tend to be smaller than those on the Dark Moorland. It is not unusual for there to be hard to see paths through what looks like solid terrain. Stone, iron and oil sources are plentiful, and often in large patches, however this further reduces the useful building space, making finding a good spot to put housing difficult despite the openness of the terrain. Like the Frozen Highlands, green patches suitable for farmland are fairly rare, forcing you to expand aggressively toward fertile areas if you are to keep your population growing.
The challenge lies in the combination of a low number of grass tiles, and higher than usual zombie aggression resulting in both food shortages and large groups of zombies coming to investigate even the smallest disturbance. It requires great skill and maybe a little luck to beat this map at the higher difficulty levels. Expect to lose a lot on this map, as it is about three times harder than the first three maps. Challenging on map 4 is considered by many to be much more difficult than Brutal on any of the earlier maps.
The Caustic Lands