Containment

Containment refers to the process of capturing, imprisoning, and exploiting Entities.

Summary

Containment is the desired end result when encountering Entities. Colonies can hold entities on a Holding spot or a Holding platform, the latter of which requires research and steel to build. Once contained, entities can be researched or regularly harvested for resources or power.

Only creature entities are placed on holding platforms. Item entities, such as the Cube, can be hauled around and placed in stockpiles - having an important stockpile dedicated to entities may be a good idea. Building entities, such as the Monolith, must be studied in their current location, as none of them are mobile. Be careful about integrating them into your base designs as they may be a source of risk down the road.

Containment strength

Any containment room is subject to containment breaches, the equivalent of prison breaks for entities. The containment strength of the room can be viewed by clicking on the platform. Containment is the sum of the following factors:

• Average Wall HP/10 (e.g all wooden walls have 195 hp and will result in +19.5 containment)
• Average Door HP/5 (an open door provides −0 containment)
• Average light level/10 (realistically limited to +5 through use of normal lights)
• Bioferrite plate flooring provides up to +15 Containment at 100% room coverage
• Unroofed containment rooms apply a −30 containment penalty
• Holding Spots modify the resulting containment for their specific spot by ×70%
• Each additional Holding Platform inflicts a roughly −10% exponential cumulative penalty to all holding platforms in the same room.
• An Electric inhibitor increases containment by +10
• A Shard inhibitor increases containment by +20
• An Electroharvester lowers containment by −25
• A Bioferrite harvester lowers containment by −15

The walls and doors that make up the containment room contribute to containment strength based on the combined average of their HP, with stronger materials (e.g: granite or plasteel) having a higher contribution. Naturally occurring walls with HP greater than naturally occurring granite have their containment strength clamped. This relies on the structures' current HP, not their maximum HP, meaning that having damaged walls or doors will result in a lower containment strength. This effect only applies to fully enclosed rooms. If any door is held open too long, the room will no longer be considered enclosed. Holding Spots and Holding Platforms should be placed with a 1-tile gap from doors to prevent colonists from triggering spurious insufficient containment warnings by keeping doors open while interacting with void entities.

Larger and more dangerous entities generally require more containment strength. An entity can be held in a weak cell just fine in the short term, it simply increases the rate at which they will break out. As a general rule, the average frequency of breaches for entities that are sufficiently contained is measured in years, while the frequency of those insufficiently contained are measured in days. This is still likely to be enough time for an unprepared colony to quickly set up an adequate cell.

The size of the cell does not affect containment strength. Note that storing multiple entities in the same room will increase the required containment strength. This may still be worthwhile for harvesting certain resources more efficiently.

An entity incapable of moving will never breach. This includes entities with broken spines, or entities with destroyed legs and insufficient arm strength. Such entities can even be held outside in a holding spot without any risk, and are a useful resource to a colony.

Although possible, surrounding a containment spot with doors results in lower containment strength than using a room with both walls and doors.

Material comparison

The following table is for roofed containment cells with walls and a single door made completely out of the listed material, with a separate column for containment cells with walls of the listed material and a security door instead of a single door of the given material. The listed values include no bonuses for flooring, lighting, or containment boosting buildings, and are for containment rooms with a single Holding platform.

Material	Containment Strength	With Security Door	Material	Containment Strength	With Security Door
Jade	31	175	Gold	37	178
Wood	40	180	Silver	43	181
Steel	62	190	Marble	74	196
Slate	81	199	Sandstone	87	202
Limestone	97	207	Granite	105	211
Bioferrite	132	220	Uranium	155	235
Plasteel	174	244

Escape Interval

The chance an entity will escape is determined by their escape interval. Each entity has a base escape interval (specified as a mean time between in days).

The entity cannot escape if:

• Their base escape interval is zero or negative. Entities incapable of escaping are:
  • Nociosphere
  • Fleshmass nucleus
• The entity is incapable of moving (missing legs or incapacitated).

The base escape interval is then further modified by:

• Entity's moving capacity
  • It is multiplied by (10000 / Entity's Moving Capacity)%
  • The moving capacity is clamped between 1 and 100%
  • For example, at 70% moving it'll be (10000 / 70) = 143% (rounded up)
  • At 100% moving, it'll just be (10000 / 100) = 100%, meaning it'll not affect the escape interval
• Days in captivity
  • At 15 days or less, it doesn't affect it at all (multiplies it by 100%)
  • At 60 days, it multiplies the escape interval by 120%
  • At 120 days, it multiplies the escape interval by 150%
  • At 240 days or more, it multiplies the escape interval by 200%
  • It scales linearly between the values
• Containment strength minus entity's minimum containment strength (so if an entity needs 30 and the containment is 50, the value is 50 - 30 = 20)
  • Below 0 strength multiplies the escape interval by 5% (lowers it significantly)
  • At 0, it doesn't affect it at all (multiplies it by 100%)
  • At 100, it multiplies it by 300%
  • At 200 or more, it multiplies it by 800%
  • It scales linearly between the values
• Temperature
  • At 0°C and above, it doesn't affect it at all (multiplies it by 100%)
  • At -30°C and below, it multiplies the escape interval by 150%
  • It scales linearly between the values
  • Affected entities:
    • Fleshbeasts
    • Shamblers
    • Ghouls

Containment facilities

There are a handful of facilities that can be constructed alongside holding spots or platforms. Some facilities help to make entities easier to contain, while others allow you to exploit entities for resources.

Building	Research	Cost	Limit	Effects
Electric inhibitor	Entity containment	2 Components,  25 Steel	- 6 per holding platform - Max distance: 4 - Min distance: 1 - Must be pointed at platform - Requires line-of-sight	- +10 containment strength
Shard inhibitor	Entity containment	15 Steel,  1 Shard	- 1 per holding platform - Max distance: 5.9	- +20 containment strength
Bioferrite harvester	Bioferrite harvesting	50 Steel,  1 Component	- 1 per holding platform - Max distance: 5.9 - Requires line-of-sight	- −15 containment strength - Produces bioferrite
Electroharvester	Electroharvester	1 Component,  25 Bioferrite,  50 Steel	- 1 per holding platform - Max distance: 5.9 - Requires line-of-sight	- −25 containment strength - ×50% entity study rate - Periodically applies electrical burns to entities - Produces up to 2000W of power

Containment Effect on Dark Study

The amount of Dark Study gained while studying contained entities is affected by containment strength. In general, the higher the containment strength over the minimum containment level of the entity then the larger multiplier of Dark Study.

If the entity is contained at exactly the minimum containment required then Dark Study is not adjusted from the base value.

At containment levels below the required amount, Dark Study is multiplied by 50%.

At containment levels 100 above the required amount, Dark Study is multiplied by 130%.

At containment levels 200 above the required amount, Dark Study is multiplied by 150%. This 50% additional Dark Study amount is the maximum value possible from containment.

In between minimum containment required and 200 additional containment the Dark Study multiplier is linearly interpolated.

Dark Study Effectiveness

Analysis

Higher Containment values lower the frequency of entity escape attempts, making it worthwhile to maximize them:

• Use a Security door for an immediate gain of roughly +160 Containment.
• Use the highest HP wall and door materials possible- which will generally be naturally occurring ore deposits, natural stone walls, Plasteel, Uranium, Bioferrite, and Granite, in that order.
• Ensure the rooms are lit and covered by a roof
• Avoid the 30% containment penalty from using Holding spots. Use Holding platforms instead.
• Use Bioferrite plating for flooring
• Do not keep entities with a high minimum containment stat in rooms with multiple holding platforms

Containment boosting buildings come with downsides- Shard inhibitors require a Shard to construct, and Electric inhibitors take up a lot of space and can only affect a single platform at a time. Shard Inhibitors are generally better suited for negating the penalties associated with Bioferrite harvesters and Electroharvesters or utilizing multiple platforms in a single room, while Electric Inhibitors are well suited for use with especially dangerous or annoying specimens (e.g: Revenants).

Maximizing Research Gains

• Do not use Bioferrite Harvesters or Electroharvesters as they reduce containment and the Electroharvester also inflicts a −50% penalty to research gains.
• Do not use multiple holding platforms in a single room.
• Ensure the room is lit
• Consider having colonists use Voidsight serum

Bioferrite Harvesting

• Prioritize capturing Toughspikes, Gorehulks, and Noctols, which give good amounts of Bioferrite while still having low or manageable minimum containment requirements, which makes them well suited to rooms with six holding platforms. None of them are particularly threatening in combat.
• Metalhorrors and Devourers require very high minimum containment strength and are unlikely to survive frequent escape attempts.
• A Revenant that escapes is highly annoying. Trispikes and Bulbfreaks will split when damaged which is very annoying and reduces future bioferrite gain even if parts of them survive, which makes them poorly suited for Bioferrite harvesting.
• Realistically Bioferrite Harvesters can only reach 6 Holding Platforms at once, which will decrease Containment. This can be partially offset by using a Shard inhibitor.
• Even with marble walls, a lit containment room with six holding platforms, bioferrite flooring, and a shard inhibitor will reach ~130 containment, sufficient to give Noctols a prison break interval of roughly 2 years.

It is possible to use Hypothermia to render Toughspikes unable to move after frostbite destroys their limbs, which makes it impossible to escape regardless of containment strength.

A downed a high-risk entity can be stored in a cryptosleep casket until a suitable containment cell can be constructed, if one is not available.

Trivia

The highest possible containment score is 403.9, possible only by having a roofed containment cell whose entirely made of unmined Plasteel ore, with a security door, bioferrite plating floors, six electric inhibitors, and a shard beacon- lit entirely by Sunlamps. A healthy Metalhorror, the entity with the highest containment requirements, would have a prison break interval of 8 years with such a setup.