Blood Moon Horde

\*This article does not apply to console version.

The **Blood Moon Horde** is a special Horde which only occurs during the Blood Moon, which on default settings occurs every 7 days (this is modifiable; see #Blood Moon Frequency below). The name of the game is a reference to this every-seven-day attack.

**The descriptions below are accurate as of Alpha 18.4 and except where noted assume default game settings and no installed mods.**

## General Concept

A Blood Moon Horde consists of an early-morning indicator, late-afternoon warnings, an initial attack followed by subsequent waves of attack, and the conclusion at 4AM. The zombies spawned during a Blood Moon Horde know exactly where all players are regardless of quiet, lack of heat, sneaking, or defenses. They will climb or dig as they are able in order to reach the player. Upon someone's death, the zombies targeting them will despawn and the Blood Moon Horde will cease for the remainder of the night. The only known way to completely avoid a Blood Moon Horde is to be on top of a tall enough POI such as the Hospital or Joe Bros Builders. It is believed that this is due to the player being too far away from valid locations for zombies to spawn on the Blood Moon.

### Indicator and Warnings

At 08:00 on Blood Moon day (this can be customized), the day number in the HUD will turn red. This is your first indication that the horde will be coming that night. At 18:00 you will hear a crack of thunder and the sky will slowly start to turn red. By 21:00 the sky will be very red and the storm will be in full swing. You are definitely running out of time!

### Initial Attack at 22:00

At 22:00 there will be a directionless scream announcing the beginning of the horde. Shortly thereafter a number of zombies will spawn some distance away from you and run towards you. The exact number of zombies depends on several factors including your Gamestage, the number of players if multiplayer, and performance settings. See #Horde Spawning Mechanics below for details.

### Subsequent Waves

As you kill zombies, more will spawn to take their place. Eventually you may kill an entire wave in which case after a short delay a new wave will begin to arrive. Each wave also has its own timer such that if you can't kill the entire wave in time it will stop spawning and the next wave will begin. This is generally invisible to the player, but see #Horde Spawning Mechanics below for details.

### Conclusion at 04:00

At 04:00 the Blood Moon Horde will end. The sky will turn from red to clear and horde-spawned zombies will return to normal behavior (slower movement, no GPS to you).

## Blood Moon Frequency

On default settings, the Blood Moon will occur every 7 days. Both single-player and dedicated server games can modify this (or disable it entirely). The two related settings are:

 Blood Moon Range | BloodMoonRange | 0 | The number of days, in addition to the 'base', that the Blood Moon can shift later than normal.

Note that each Blood Moon Frequency setting is *relative to the previous Blood Moon*. The next blood moon occurs on frequency + the range.

**Example 1:** Setting frequency to 7 and range to 1 means that the first Blood Moon might occur on day 7 or 8. If the Blood Moon is on Day 8, then the next Blood Moon might occur on (8 + 7 + up to 1 day), meaning days 15 or 16.

**Example 2:** Setting Frequency to 10 and range to 3 means that the first Blood Moon could be on days 10-13. If the 1st occurs on day 12, then the 2nd will occur on (12 + 10 + up to 3 days), meaning days 22-25.

**Example 3:** Setting Frequency to 1 will cause a Blood Moon every night, if you're into that sort of thing.

Blood Moon Frequency Updated for Alpha 20.0 b238

## Horde Spawning Mechanics

### Simplified

The simplified version of the mechanics are this:

1. Number and strength of waves is determined by your gamestage
2. The number of actual zombies you will fight at any one time is determined by gamestage, number of players, and game settings
3. Each wave has a total number of zombies and a timer - either killing an entire wave or running out of time will start the next wave (any remaining unspawned zombies in the current wave will not spawn)
4. As of Alpha 18.4, the waves are finite; if you can kill all of the zombies in the final wave there will be no 'trickle' of zombies the remainder of the night (it can be added back in through a modlet, however)
5. At 04:00 all remaining Blood Moon-spawned zombies will revert to normal behavior

### The Full Details

#### The File Where it Happens: Gamestages.xml

The configuration file which controls Blood Moon Horde spawning is gamestages.xml. Here is an example for gamestage 59 which we will walk through. Each <spawn ... /> line identifies a single wave of the overall horde.

```
<gamestage stage="59">
  <spawn group="feralHordeStageGS49" num="84" maxAlive="20" duration="2" interval="29"/>
  <spawn group="feralHordeStageGS54" num="84" maxAlive="20" duration="2" interval="18"/>
  <spawn group="feralHordeStageGS59" num="84" maxAlive="20" duration="7"/>
</gamestage>

```

Here is how to interpret the parameters in that block.

 interval="29" | This is the time between waves in real-world seconds; if you kill a wave or its timer runs out you will have a breather for this many seconds before the next wave

#### How Many Zombies Could There Be?

The total possible number of zombies which can spawn during a Blood Moon Horde can be found by adding up the 'num' parameter for all waves in the appropriate <gamestage> entry in gamestages.xml. In the example shown above, the total number of possible zombies is 84 + 84 + 84 = 252. The actual number of zombies spawned *at the same time* will likely be different and the total number of zombies *actually fought* might be different depending on how efficient you are at killing them.

#### How Many Zombies Will Spawn At Once?

The total number of zombies which will spawn at once - say, in the initial attack on your base - is the *lesser* of the following three values.

 maxAlive for Horde Wave X # of Players | The per-player maximum number of zombies to spawn for a given gamestage & horde wave | <depends on GS and wave> | gamestages.xml (not recommended)

**Example 1:**

* Single-player game
* Max Spawned Zombies = 64 (default)
* Blood Moon Enemy Count = 8 (default)
* Parameter 'maxAlive' for the horde wave = 22
* Parameter 'num' for the horde wave = 100

In this example, the limiting factor is Blood Moon Enemy Count, so only 8 zombies will spawn from the horde at once. As they are killed, new horde zombies will spawn to keep the total at 8.

**Example 2:**

* Single-player game
* Max Spawned Zombies = 64 (default)
* Blood Moon Enemy Count = 32
* Parameter 'maxAlive' for the horde wave = 22
* Parameter 'num' for the horde wave = 100

In this example, now the limiting factor is the 'maxAlive' parameter for the horde wave, which is 22. As gamestage increases, eventually maxAlive will grow to be greater than the Blood Moon Enemy Count setting (32) and then the limit would be 32 at once.

**Example 3:**

* Multiplayer dedicated server game with 3 players
* Max Spawned Zombies = 64 (default)
* Blood Moon Enemy Count = 32
* Parameter 'maxAlive' for the horde wave = 22
* Parameter 'num' for the horde wave = 100

In this example, the limiting factor is Max Spawned Zombies. This is because 'maxAlive' (22) times the number of players (3) equals 66 total spawns. However the Max Spawned Zombies setting is 64, so only 64 spawns would happen at once.

#### Max Spawned Zombies Setting and Natural Spawns

At the beginning of a Blood Moon Horde there may be some natural spawns in the area. These spawns *do count* against the Max Spawned Zombies limit, and the Blood Moon horde will only spawn zombies until the max is hit, even if this is less than would otherwise be allowed. So in Example 3 above, if there were 10 naturally-spawned zombies milling around when the horde started, the horde would only be able to spawn in 54 zombies (64 max minus the 10 already in the world) to start with. Eventually the natural spawns will time out (or be killed) and pretty much all living zombies will be from the horde spawner.

#### Kill 'Em All vs Horde Wave Duration

Each horde wave has a duration expressed in in-game hours. In the example above the first two waves have a duration of 2 hours and the last has a duration of 7 hours. Note that the entire Blood Moon lasts for 6 hours, so a duration of 7 essentially means 'for all the time remaining until 0400'.

When fighting or evading the horde, there are three possible results for each wave:

1. You kill all of the zombies in the wave (the 'num' parameter) - in this case the next wave will start immediately after the 'interval' parameter of the wave you killed
2. You fight/evade the wave until its duration expires - in this case the next wave will start after 'interval'; any remaining zombies still must be killed or evaded
3. You fight/evade the wave until 04:00 - in this case all remaining zombies will switch to normal behavior and you can clean them up or evade them like any other zombie

If you repeatedly achieve result #1, it is quite possible to 'beat' the Blood Moon well before 04:00. After that there will be no more spawns (see #Customizations below). If you at least achieve result #1 on the final wave, you will 'beat' Blood Moon and spawns will cease. At higher gamestages this is increasingly difficult as the waves are more numerous and have a larger total spawn amount.

## Multiplayer and Performance Considerations

The primary differences between single-player and multiplayer hordes are the per-player horde spawn limits. These are 'Blood Moon Enemy Count' and 'maxAlive' described above. Generally you will not want to mess with maxAlive unless you are building a mod, so to adjust the multiplayer experience you will want to adjust Blood Moon Enemy Count. Increasing the value will - especially as your gamestage passes about 50 or so - make the 'horde fight' bigger in a very direct way. Double the value and you will see double the zombies attacking your base at the same time. This has significant performance impacts for both the server *and* the clients.

The global setting affecting single-player, multiplayer, and performance is Max Spawned Zombies. Increasing this value will allow more zombies in your world *at all times* as well as lifting the ultimate cap for Blood Moon hordes. This is a hard limit for the entire game so, for example, in a 4-player game setting Max Spawned Zombies to 100 while having Blood Moon Enemy Count at 30 will not make a lot of sense, since the 4 x 30 = 120 desired max for Blood Moon will be capped by the game-wide Max Spawned Zombies setting of 100.

## Customizations

The following customizations are just a sample of changes you can make to adjust the Blood Moon Horde to your liking.

 A guaranteed non-stop final wave | Edit appropriate final <stage .../> entries (within each <gamestage> group) in gamestages.xml to change num="9999"

## Notes

* In A19+, if you are outside in the open from 00:00 to about 04:00 on the day of the Blood Moon Horde, you will occasionally see a mist form and turn red. (Possible bug)