Rimworld’s Anomaly DLC has you managing and containing unnatural entities. They function quite differently from humanoid prisoners or penned animals and the cost for mistakes can be significantly higher. A normal prison break ends when the captives escape to freedom. An escape in Anomaly can mean researchers getting eaten alive before the guards arrive.

A well-run containment facility can reward the player with forbidden knowledge, new psychic powers, bioferrite weapons, and weaponised entities. Here is everything you need to know about how to lay out your cells, upgrade your cells, and use the captive entities for the benefit of your colony.

A bioferrite farm in Rimworld, with sightstealers, shamblers and a toughspike being harvested

How To Build Containment Facilities

Each entity you encounter in the game will havea minimum containment strength. You ideally want to be well above this amount to minimise how often they try to escape. There are both universal and specific factors to containment strength.

Building Material

The biggest factors in containment strength are the building materials you use. These are tracked separately for your holding spot, walls, and door.

You can use the HP of the material as the main deciding factor, as this is what directly scales containment strength. Other factors have some secondary relevance:

A high security cell, with plasteel walls and banks of electric inhibitors

Layered walls have no impact on containment but can still be useful. A plasteel cell can be given asecond layer of stone bricks for fireproofing.

Doors follow the same rule as walls,examining the HP of the material used. You want to have only one door to these cells. The newly added Security Door is the best choice for this but needs plasteel and electricity.

A rimworld prison contains fleshbeast anomalies by keeping the temperature below freezing

Holding platforms are your second consideration. The free-to-build holding spot can be used in a pinch but thesteel holding platform give 40 pointsof containment. A wooden shack with a steel holding plate can be cheaper than a steel building and basic holding spots.

Items To Boost Containment

There are both DLC-specific items to increase containment and repurposed tools from the vanilla game.

How Many Entities To Store Per Room

Space is a limited commodity when building bases in Rimworld. You want your entities locked up as close to the middle as possible, so it doesn’t get damaged during firefights or dug into by sappers.

Unfortunately, each holding spot in a room weakens the containment of the others. Thisapplies even if the spots are empty, so only build spots when you need them.

A freezer filled with slain entities from Rimworld’s Anomaly DLC

You also want to store your captives close together to benefit from the shard inhibitor upgrade. Either place the inhibitor in the walls between several rooms or in the centre of a room surrounded by holding spots. Upgrades like the bioferrite harvester and electroharvester draw from amaximum of four platforms. This is a good upper limit for entities that don’t warrant a personal cell.

All Containment Thresholds

Stronger anomalies need more security, but the precise thresholds are malleable: You don’t want a security system that meets the minimum requirements (especially if it is dependent on electric inhibitors and lights that can beknocked out by a solar flare). Aim instead tobuild well above each threshold.

The advanced entities will only begin appearing after you haveactivated the fallen monolith a second time.Make sure you are ready to contain them before proceeding.

Four captive entities share a cell in Rimword. The walls are stone and the floor is bioferrite.

Example entities

Sightstealers, shamblers and weaker fleshbeasts

A group of sightstealers fails to escape from containment and are gunned down by waiting pawns

Between 30 and 60

Asteel-walled room with a normal steel dooris enough if you don’t store too many in a room.

Replace holding spots withsteel platforms and rebuild the walls from stone.

Between 70 and 110

Nociosphere

Requires a warden to suppress it

The Nociosphere cannot be prevented from escaping once a certain time limit passes. Before this happens,send it to exhaust itself killing mechanoids.

The Nociosphere can defeat an Apocriton-level raid.Any less and it’ll turn on you afterwards.

Handling Escape Attempts

Escape attempts work similarly to humanoid prisonbreaks with two major exceptions. A human cansteal the keys to open doors, allowing them to walk out quickly. If there are available weapons they’llarm themselves on the way out.Anomalies will break free from the restraints on their holding platform but must still force down the door to escape. They can’t pick up weapons but have full access to their natural abilities.

The nearly 1,000 hitpoints of the security door mean you’ll have plenty of time to assemble a security team. The issue is that allowing them to fully destroy the door enables other anomalies still chained up to make additional escape attempts. In large prisons, this can quickly cascade.

The safest approach is toopen the door with a melee unit,either a well-armoured pawn, ghoul or mechanoid. You’ll want to run back andfight away from the dooror else other entities will attempt to escape.

Unless you bringnon-lethal weapons such as blunt melee and nerve spikers,you’re able to expect some of your escapees to die instead of being recaptured. You can temporarily uninstall their holding spots to improve security on the remainder.