RimWorld Biotech adds the ability to create interesting humanoids that can spew fire, eat dirt, and live forever.

With the help of the genetics system added to this DLC, you can have more fun than ever in RimWorld.

Recommended Read: What Happens After You Build a Spaceship in RimWorld?

However, there were a lot of things added, and you won’t really understand anything by just looking at all those genes.

So, here is an extensive guide explaining genetics, how genes work, what types there are, and many other things regarding the Biotech system in RimWorld.

How Does the Genes System Work in RimWorld

The genes system exists to help improve your pawns into supernatural beings in RimWorld. From vampires to fire imps, you can create any type of humanoid being using genetics.

You can create all of these unique humanoid beings using special genes. Each special gene can have positive and negative traits.

There are around three buildings that you will have to construct and use to start creating these advanced humanoids, which will have two types of genes.

All Gene Types in RimWorld

There are two major types of genes that your pawns can have:

• Germline genes
• Xenogenes

Germline genes

Germline genes are genes that you can inherit and pass on to your offspring. A pawn with specific germline genes will always pass them over to their child.

A pawn can get Germline genes (or Endogenes) from their parents or at the start of the game through the scenario setup.

There is no way to change Germline genes. You can’t remove them or add more to your colonists during your playthrough.

Xenogenes

Xenogenes are genes that you can implant into your pawns. You can change, remove, and add Xenogenes to your colonists at any time.

Xenogenes are not inherited by children. This means that whatever changes you make to a pawn will not remain for their child.

The Xenogenes will override Germline genes. If you had, for example, a Germline gene that gives a pawn red hair and gave them a Xenogene that gives them blue hair, they will have blue hair.

Each gene that you will find in RimWorld has a gene complexity number and a metabolic efficiency one.

Gene complexity will always be a positive number, and metabolic efficiency can be positive or negative.

Gene complexity is a number that represents how hard it is to assimilate a gene into a genome. Complex genes are much more difficult to assemble and implant into a pawn.

If you have a complex gene, then it will also take longer for it to regrow if you extracted it at the gene extractor. We will explain gene extraction in more detail below.

Metabolic efficiency represents how hungry your pawn will be. The higher your pawn’s metabolic efficiency, the less hungry they will be.

If you tried to make a really powerful pawn with only good genes, they would most likely have to eat as many as 10 people in a day.

So, good genes have negative metabolic efficiency and bad genes have positive metabolic efficiency.

The hunger rate that you can get due to genes has caps. You can have a minimum of -5 metabolic complexity, which will give your pawn a hunger rate of 225%.

On the other hand, there isn’t a cap on the positive metabolic complexity a gene can have. However, the best hunger rate you can get is 50% at +5 metabolic complexity.

Luckily, there are many genes that have a 0 in both gene complexity and metabolic complexity. Almost all the aesthetic genes (hair color or physical traits) won’t have a number in these two categories.