Blood rain

This article is about the event. For the psychic ritual that can cause the event, see Blood rain (ritual).

A turgid blood-like psychofluid that falls from the sky. Anyone exposed to it feels a growing anger that eventually becomes a berserk rage.
— Entity codex

Blood rain is a weather-like^[Like?] Major Threat added by the Anomaly DLC that induces the blood rage hediff on pawns and animals. It causes colonists to get wet and apply the −3 Soaking wet mood for 0.1 days as well as affecting aim the same as fog (reducing weapon accuracy to 50%).

Blood rage increases melee damage factor but decreases mood and can cause animals to go manhunter or pawns to go berserk. It does not affect dryads, mechanoids, drones, or entities (with exception of humanoid entities like ghouls and shamblers).

Severity gain rate of blood rain is determined at the moment a creature gains that hediff and cannot change until they lose it. The base severity gain rate for Blood Rage is between 16.5% and 27.5% for humans and humanoid entities, and between 2.2% and 17.6% for animals (chosen randomly when gaining the hediff). The severity gain rate is then cut in half for pawns with the wimp and kind traits (stacking together for 75% reduction). The severity gain rate is then multiplied by Psychic Sensitivity, so 50% will cut the severity gain rate in half, and 200% will double the rate at which severity raises. Pawns with 0% Psychic Sensitivity (which includes ghouls and shamblers) will receive the Blood Rage at the initial, very mild (hidden) stage, but it will never raise. Once a pawn gains the Blood Rage hediff, trying to change their Psychic Sensitivity or traits won't affect their severity gain rate until they lose this hediff and regain it. This also means that if a pawn is affected by blood rage and then turned into a ghoul or a shambler they'll keep gaining severity despite otherwise being incapable of doing so.

As long as the pawn is protected from the blood rain, the severity of the hediff will fall at a rate of 33% per hour (regardless of any other factors).

The Blood Rain event lasts between 8 and 36 hours.

Severity	5%< Very mild	5%> Mild	40%> Moderate	60%> Severe	80%> Extreme
Melee Damage Factor	-	110%	125%	137.5%	150%
Mood Impact	-	−6	−12	−18	−24

At 100% severity, the pawn goes into a Berserk state and won't fall asleep until they are no longer exposed to blood rain.

This event can be fired as a major threat or triggered by rituals.

Analysis[edit]

Blood rain is a relatively harmless major threat. Simply keeping pawns indoors and under a roof, like toxic fallout, will prevent all detrimental effects. Unlike toxic fallout, crops are not destroyed, and the rain does not last long enough for food to be a major issue. An allowed area can make it easier to control where pawns move. Alternatively, to prevent pawns on mental breaks from wandering out, you can wall in the exits to your base.

Beware that animals on the map will also become enraged, acting as standard manhunters. They will attack any raiders, including mechs, that arrive during a blood rain.

The blood rain ritual can be a good way of dealing with sieges, and, since it enrages animals, it can also be used to damage mech clusters. The ritual is otherwise too slow to enrage other types of raids. However, it could be used pre-emptively to enrage animals on the map when knowing that a raid can happen, e.g., when accepting a quest, starting the ship reactor, or fighting a mechanitor boss.

History[edit]

Anomaly DLC Release - Added.
1.5.4067 - Increased the upper end of blood rain duration for both the incident and psychic ritual.
1.5.4083 - Blood rage at 100% now forces animals to be awake.
1.6.4850 - Fix: Bloodrage hediff increasing/decreasing too slowly on pawns ticking at a lower rate.

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