RRS = Random Resource Spawn. The spawns of gold, wood, stone, iron, oil that appear on the map mostly near your starting point.

VoD = Village of Doom

Zombie Raid:
The zombie waves that will periodically attack your colony from 1 direction and getting bigger with each wave(Not to confuse with RZS!).

RZS = Random Zombie Spawns
From day 20 there will be periodically spawning Zombies (containing only runners) from all dircetions who will run to your colony and attack it. (Not to confuse with Zombie Raids!)

This section is a general collection of Tips & Tricks that will help you to get a better understanding of the game and will help you to get your first win or climbing up that difficulty percentage.
Some of these Tips you will find in other parts of this Guide so don't get confused about that.


Right at the beginning of the game you want to send your Rangers in different directions to explore your surroundings. This way you can find RRS for that delicious early game boost and can get a better image of where you want to expand later, where you gonna place your houses, your farms etc...
Just don't explore to deep, be careful with runners. If a harpy spots your ranger... rip.

Use the soldier
Right after that you should already start clearing out zombies close to your village your village.
The soldier is very effective doing this! He can take on multiple zombies (slow ones) at once, but stay close to your village until because he will easily attract runners and they can become a problem when your army is not yet strong enough!

// Question to my readers: Is this part (early aggression) to advanced for new players? On lower difficulties you normally have enough place at the start, so early aggression is not that important. You can build an army of rangers first before attacking your surroundings, but it's definitely necessary on higher difficulties. Please tell me in the comments or per pm! Thank you.


Completely surrounding yourself early with walls/towers is a waste of gold and wood which is much more needed in building up your economy and training units.
In the early game patrols of rangers (1 or 2) are more than enough to keep zombies out of your colony (most of the time). It's completely fine to place some small walls at choke points and especially in direction of VoDs but just don't do something like this:

Wood/Stone Towers extends the range of the units inside. Good for defending against runners when you don't want to kite and just want to hold a place without having to manage and concentrate on it all the time. Don't build to much of them (same as walls).


1 piece of wall can safe your colony!
Zombies attack everything what is directly in their path of them and don't walk around it (except when they are chasing a unit). Placing 1 piece of wall in front (in direction to the zombies) of a building will make the Zombie attack the wall. First of all this will throw the "warning alert" (Your defense is under attack), secondary you will get a small time buffer to react against the threat, before the zombies can threaten your buildings.


Starting at around Day 20 (kinda with or after the 2nd Zombie Raid) there will periodically be RZS that come from every direction and will attack your colony.
Until that day you should have expanded to natural choke-points and seal your colony off with little walls and patrols or Ballistas (one per choke/wall is enough) near them.

Another reason not to surround your colony with walls early is, that you want to expand.
This game rewards an aggressive expansion play style, when done correctly.
When you want your economy to grow there is no other way than to extend as often as possible to acquire more room for farms, quarries, houses. You need to push up your gold income over the game and the only way doing it, is to place down farms and mills and they need space!
Always try to extend your colony to choke-points that you can defend easily against Zombie Raids.
The best time to extend is probably right after a Zombie Raid, but be careful with RZS. Always protect your expansion with troops.

First of all: Economy = Everything. Gold-,wood-,....,income, food-supply, energy-supply, workers/houses. Everything is important. You need to push everything of your colony kind of simultaneously. Of course you will go low on resources or supply but that's fine. You need to find the right balance between pushing your economy, training units, expanding your colony and building your defense.

Especially towards endgame you need to build a great amount of Stone-Quarries to get your Stone-Walls and Executors up! Even if you may cap your stone supply sometimes, you should have at least 40+ stone-income when starting to build your final defenses!

You should aim to get 1800-2000 colonist at the end of the game around 10 days before the final wave (day 82 on "100-Day-Game"). This can be hard if you are new to the game and you probably won't be able to do it. Just keep it in mind!


When the final wave arrives all zombies on the map, including the ones inside VoDs trigger to attack your colony. Therefore it is important to clear the map from zombies and VoDs once you have a decent army (preferably Snipers, read more about this in the Strategy Section).
Killing Zombies also gets your troops to that sweet Veteran-Status which i will explain later.
For example to clear a village of doom (on 100% difficulty) you need approximately 15 snipers.
After wave 3 you should definitely start to clear VoDs. On Map 2 there are 6 VoDs (!), so you better start early.
Villages of Doom also drop a huge amount of resources!


Try not to get into the situation where you are fighting with your army on one side of the map and then getting the alert that a wave is coming from the other side. There are approximately 10 days between each wave so keep that in mind. Move your forces back to your colony a day before you think the wave could arrive to be prepared. Also don't attack VoDs right before a Zombie Raid!



A common mistake is to start making a fortress out of your colony to early. If you build a lot of Executors your gold income will drop down significantly! Always keep and eye on that. Building up walls has no real downsides so focus on that first. If you have trouble planning where your Executors will stand build Ballistas and upgrade them later because they have a much lower upkeep cost. You should start preparing your final defense roughly 10 days before the final wave comes.

//Endgame Still under construction
Endgame Defenses
Important: Before reading this part, go to the "Units & Towers - Section" of this guide and read the information about towers.

For endgame walls you want to have "double-walls" with towers in-between. Remember to support your Shocking-Towers.

Example for a bad defense:
The Shocking-Towers will die really fast to harpies and spitters and just 2 Executors will probably not hold the line. It might clear a a lot of trash zombies but chubbies will be a big problem!

Better:
The Shocking-Tower probably will survive very long because every thread to it will be removed from snipers and the Executor.

More Examples for good defenses

Without Thanatos -------------------------------------------- With Thanatos

Use it. Use it often. And don't let anyone tell you how to play the game (not even me, i'm just giving you tips ;) ).

Standard units (Rangers, Soldiers, Snipers) reach a "Veteran-Status" once they killed enough zombies. With the "level up" they gain double attack speed and double damage. Snipers get even more powerful then they are already!


(This does not apply to Zombie Waves)
It is generally bad to mix different units to fight zombies unless you want to use intensive micromanagement (it's up to you).
Rangers are mainly used to silent clear surrounding zombies.
Snipers are mainly used to clear the map (so you basically want zombies coming to them).

When mixing Snipers and Rangers for example, the following things can happen:

1. Clearing surrounding Zombies:
Your Snipers noise will attract a lot of runners and special infected which can easily overwhelm your rangers.

2. Clearing the map: Your Rangers will run ahead of your snipers because there are a lot faster and also have a shorter range. This makes the rangers vulnerable to all kind of special infected and will probably result in losing some of them when running into an area that has a lot of special infected.


Units/Towers like Thanatos and Shocking-Towers need support from either other turrets or snipers
that kill special infected like spitters (for Shocking-Towers) or harpies (for Thanatos).


Only upgrade buildings (such as tents or mills) when you run out of space and/or cant see any opportunity to expand in near future.

Example: Mills
An advanced mill only gives 2x the energy of a normal mill but has 7x the upkeep cost.
So placing just another normal mill will keep your goldincome higher.

Houses
1 Cottage gives +2 gold over 2 tents, but costs way more (120 gold 12 wood against 60 gold) so if you have space left in your housing area build more tents. Cottages and especially Stone-Houses also cost you more energy.


The Mayors appear at 20 / 200 / 600 / 1200 colonists.
Getting to the Mayors is pretty benefiting and you should aim for getting them.
You get your first Mayor if you build 7 tents.

There are some bad, a good chunk of good and some amazing Mayors, but I will not compare them here. You should pick the one which fits your playstyle.

Still the best first Mayor is probably "TechFarm" because Farms are so important early and you can build them before even having to build a wood workshop getting a huge early boost.

Be careful with Superunits from the 2nd Mayor like Lucifer or THANATOS. They are pretty loud and especially Thanatos can trigger like the whole map to attack you ( Map 4 = instant lose). The 3rd Mayor can give you a Titan who is also pretty loud but at this time you
should be busy clearing the map anyways. ;)

Resource Mayors are often bad because you are capped (or nearly capped) anyways and the resources will be wasted.

Building oil-platforms, quarries, sawmills etc... outside your defense line is not a bad idea at all!
As long your defenses at this point are strong enough there won't be a difference between some more infected if the building gets taken down by zombies. Just repair it afterwards!


Everything "fighting" that happens on your screen (what you can see) will not result into an alert and can lead to loosing units.
Keep that in mind when zooming all the way out.


Be careful when refunding researches or buildings when you are not in pause mode. You only get half your staff back. (Accidentally researched Ballista and canceled it without pausing? rip 350 gold)


Don't cap your resources at start when collecting random resource Spawns. You can cap your gold very easy at the beginning.


Disable Production
When you don't have the market yet disable sawmills/quarrys. *when storage is full*
Don't forget to turn them back on once you got the market.


Pressing the Alt Key shows all health bars above all units and buildings.
Use it to "spot" zombies trying to sneak into your base.

Pressing TAB toggles the visibility of the UI.


Be careful with those early game. They "detect" sound just like zombies and can trigger even if you are not attacking them. If they are close to your base at start, build a small wall between base and VoD and patrol it.
In the mid game you should have a decent army that can take out these villages pretty easily (e.g. 20-30 snipers). The destroyed buildings will drop a lot if resources, which will be a great boost to your economy. You can also build 3 ballistas near them and trigger them and let all the zombies run into your ballistas.
You should always try to kill all VoD on the map before the final wave arrives because once the billions are coming VoDs trigger all their Zombies inside them to attack you anyways.

Going out of Energy or Food is often not a problem you just build a Farm/Mill and you are fine. But going out of workers and food/energy at the same time can be quite devastating because you probably need energy/food to build more tents to get more workers, but you can't do that, and it could take you a while to get out of this loophole. So try to keep and eye on your amount of workers.

Kiting Zombies is very important in They Are Billions. You might say: "I never kited zombies, there is no need for it" and that's true for lower difficulties but once you get to higher difficulties or Map 4 in particular you are going to need it.

It can take a bit of practice but it's not really that hard.

Basically you clump up your troops, set them on hold ("H") and take one ranger who takes all the aggro. Let them chase this Ranger and let the group kill them while you run "circles".

There are two occasion when to kite.

1. Alot of runners coming at your squad ---------------- 2. The waves of Zombie Raids

While both videos are without pause you can/should of course use pause to minimize casualties.

How many waves you can kite depends on your infected population setting.

For example on max infected population you can kite the first 2 with rangers. For the next you probably need snipers.


3rd Wave on Brutal

This Game doesn't really have a Build-Order like other RTS-Games Starcraft, but still has some key buildings to get in an order early game. Notice that this is a general strategy and can differ every game just because of how random this game is.

I will also try to keep this early game build order as general as possible without impact from Mayors (e.g. TechFarm) and without
without RRS and basically without scouting. Please also keep in mind that it's not necessary to get some building at precises times.
If you get the Soldiers center at day 2 or at day 4 doesn't make that much of a difference because you not gonna have the resources at day 2 to pump out rangers constantly anyways. So building up your economy first is fine too.

- Scroll down for detailed version

1. Huntermans/Fishermans Cottage
2. 7 or more tents
3. Sawmill
(Now expand and build food production and tents whenever you can)
4a. Have 20 Stone? -> Soldiers Center
4b. Still need stone? -> Quarry
5. Wood Workshop (Quarry after when not build yet)
6. Research Farm
7. 2nd Sawmill (you can build it earlier too)
8. Build Farm(s)
9. Get to 200 Colonists and research Marketplace on its way
10. Build Marketplace
First Zombie Raid hits


The first thing you wanna do at the star of every game is to build a hunters or a fisherman's cottage and then exploring the map with your rangers to find RRS. It will be finished the same time you get your first gold income and will allow you to build 7 tents which will get you to 20 colonist and your first mayor.
Next thing is a sawmill. Strongly recommended to get one with at least 10 wood income. If you don't have such a spot it can be better to build a tesla tower first to get to a good spot.
The next key building you want to get as fast as possible is the Soldiers Center. You need to get troops out as early as possible so you can clear out the surrounding zombie hordes.
You need a quarry to farm 20 stone (for the Soldiers Center). You need 30 wood to build the quarry. If you have good forest you can build 2 sawmills to speed it up but you will probably find RRS with wood anyways. You might need to build a Tesla Tower to get to a (good) stone spot.
In the mean time build more food production and spam tents. Build the quarry and keep building food and tents.
Depending on how many tents and food production you build you also need to build a mill somewhere in between.
Build the Soldiers Center and pump out rangers.
Next key building is the Wood Workshop because you need the technology Farm because you will go out of places to build food-cottages.
You should aim at day 5(or earlier) to build the Wood Workshop. Once build immediately research Farm and build it asap.
Boost your colony to 200 colonist while creating more rangers. Start researching Market before reaching 200 and build the Market asap.
You will also get your 2nd mayor at 200 colonists and should be finished at around day 10.
This is the time the first Zombie Raid will occur.

Example Start

(Difficulty Brutal 320%)

Example for Day 2-3
Production ist set up, Soldiers Center on its way, surroundings are explored, rangers on patrol.

Example for Day 6
Soldiers Center is training Rangers, Wood Workshop is researching Farm (no more spots for Fishers/Hunters already), rangers patrolling the sides, a small squad of rangers starts clearing the surroundings, tents on the way for more workers.


Example for Day 10
Soldiers Center still training more Rangers, 2 Farms build, 200 Colonist reached and Market placed down, the ranger squad still clearing space to expand, small wall between VoD and my colony. Notice also the little pieces of wall at the sides of the colony (from General Tips)

If you didn't read General Tips & Tricks you might wonder now: "No walls yet? How do you gonna protect against the Raid?". There is a video in the Kiting Section where i defend this first raid with just rangers :)

Ranger - Early Game Scout

Really fast, really quit, really cheap, dies quickly.
Pump these out early and clear the surroinding zombies to expand your colony.
Put them on patrol to protect your colony from sneaky zombies.

My to go unit early game. Just be careful when pushing too far out as runners can easily kill them.
If a chunk of runners is running towards your Ranger-Squad, fall back and then kite.

- Standard Fighter

Solid unit. Is tough and can tank normal zombies and runners pretty well.
They are expensive though and also need iron.
Be careful: can attract a lot of runners because of loud shots.

I really liked soldiers when i first got into this, but the downsides came in clear pretty soon.
Expensive compared to Rangers, kinda slow, weak range, damage and hitpoints/armor are good though.
Biggest downside is the attraction of runners and other zombies (Map 2 & 4).
You can still go for them especially on Map 3 and on lower difficulties, but if you plan to go higher you should definitely get comfortable with rangers.

- Long Range Killing Machine
Tough unit with high damage and high range.
One shots most Zombies. Extremely good against Special Infected.
More details in my Strategy-Section.


Overall Weak unit. Also loud. Definitely not meant for beginners. Slow and dies to special infected very fast. Can kill hordes of normal zombies very quickly.

This unit is super strong and the key in my strategy that the description of it will be in my Strategy- Section.

Extremely expensive research (6000 gold). Walking mini Executor. Fast, high range, splash damage.

Titans are very powerful and only a few are needed to clear all zombies on the map.
Getting to Titans is very expensive and takes a long time and might be a bad idea for inexperienced players. Don't worry to go for them in longer games (100+ days)



Ballista
Standard tower. Does small splash damage. Low Upkeep cost.

It can be pretty expensive early game, but for holding chokes and defending walls it is definitely worth it. You should have alot of them late game.
In most cases one tower is enough to defend a choke-point/wall from RZS the entire game (with wall repairing of course).

It falls off a bit in the late game against the Executor but it is still a really good supporting tower and can help defending your Shocking-Towers from spitters and harpies.

Shocking-Tower

Great to clear trash. Weak against chubbyies. Spitters are Shocking-Towers nightmare.
Decent gold-upkeep cost. Extreme energy costs!
They need to be supported by other units like snipers (best) or ballistas/executors because they can die to Spitters and harpies very easily. Set your snipers/towers priority-targeting to highest level and they will take care of the spitters.

Protected Shocking-Tower


Executor

The strongest Tower in the game. Expensive to research (3000 gold) expensive to build and high upkeep cost (60 gold). Does splash damage.
They excel at defending big waves and the final wave. They also can support Shocking-Towers very well because they kill special infected very quickly.
But careful with building them to early. If build to much they will hurt your gold income very badly! I recommend not building them 10-15 days before the final wave hits. (100 Days-> Wave comes day 92 -> start building day 80).


While they are really strong turrets and you want to get a lot of them until the final wave (no seriously GET A LOT), you don't need them to win the game. I won my first 500% Brutal game on Map 4 without any executors, because i had a terrible mid-game and just couldn't get the money. I spend most of my gold to get out more Thanatos and on Oil-Platforms. This was my first game ever not building executors.

You can see the final wave here

//Under Construction

Technologies

Advanced Farm is probably the only Advanced Tech you definitely need because of "space-reasons". You need 20 oil to upgrade it!

Advanced Quarries if you cannot excess more stone spots. Also good at gold-spots!

I talked about Advanced Mills already in Tips & Tricks already.


Power Plants grant a great amount of energy but consume wood and stone to produce it. Should not be build if you produce less then 30 stone.

Useless.


Both towers are optional.
Gives vision around it in a large area. The Lookout Tower is cheap, the Radar Tower has a much larger radius.
Can be build right when a Zombie Raid is announced to get more information about the path the raid is talking (or to spot if it splits into two groups).

They give +1 bonus range compared to wood towers, which can be quiet a deal.

\\Still under construction\\



I thought about it and right now i think this strategy is not good for beginners. Beginners should focus more on walling themselves of with a lot of turrets.


The Sniper/Thanatos Strategy is heavenly used by a lot of players/streamers because it is very efficient.

First let's talk about snipers.
Snipers in a big group is a unstoppable force who can take out every zombie hordes on the map.
For what they do they are really cheap (only 60 gold more then soldiers). They move pretty slow, but make up for that with high damage and a big chunk of life points. It is important to get a lot of these guys to Veteran Status because it doubles their attack speed (and their damage)!

Thanatos
Thanatos is one hell of a defense machine! It's a mobile defense tower and shoots with his rocket launcher that does massive splash damage and has a huge impact radius. Thanatos excel at holding lines against massive zombie hordes and is generally good against any kind of zombie except harpies.
He kills Harpies nonetheless but he goes into his melee-attack form for this and is wasting a lot of time where he could shoot his rockets. Because of this he should be supported by either some snipers or ballistas (or both). While it's generally bad to put different types of units together that doesn't apply for Zombie Waves.

You should start producing Thanatos in mid-game (day 40-50) and get as much as possible until the final wave. They are really good at defending the Zombie Raids that come periodically so getting them in mid-game will help because you because you don't have to put money into towers (which maybe become useless because you gonna expand or the next Zombie Raid hitting a different side of your colony). You can just move them inside your colony to where they are needed the most. They walk slow though but as long your colony isn't as big as the map itself they should arrive anywhere just at the right time.





Gameplan for 80 days (100 is very similar you just have more time)

Early Game (Day 1-25):
Normal Build up.
Get 25-40 Rangers and clear surroundings.
Expand your colony.
Start producing Snipers.

Midgame (Day 25-50) : With 5-10 Snipers you can already move out and start attacking deeper parts , but keep them close when you expect a Zombie Raid!
Once you get 15-25 Snipers (depends on infected population setting) you can start clearing Villages of Doom to get that sweet supply boost.
Aim to get around 35-45 Snipers and start clearing the whole map.

From mid to late-game; get a foundry and an engineering center -> research Thanatos. Remember to research and build an Oil Platform first! Even if you have collected oil to this moment you need an "oil upkeep" to produce Thanatos.

Late Game(Day 50-72)
Produce as much Thanatos as possible until the final wave and get 3-5 of them at every choke-point you want to defend. How many depends on how good the rest of the defense is like the amount of towers, snipers and how many layers of walls you have.
Also distribute all your snipers to your defenses (build some towers for higher range) to support Thanatos (and Shocking-Towers)



Here the 2 No Pause Games from the Guide Description which follow that strategy.
On Map 1 i had 70 Thanatos at the end (total overkill lol).

Map 1

Map 3








IMPORTANT: Set every snipers target priority to "highest level". Therefore the special infected (Spitters in particular) get killed first. Don't get scared with runners hitting your Snipers once.

If you feel like you will be overrunned from different sides DO NOT pull all Snipers back. Select 2/3 (from the back) -> move them back some meters while the frontline still shoots -> press "H" (set them to hold) -> move frontline back -> repeat.
Do this with a lot of pausing to reduce casualties.