# Gene Inheritance
The main focus here is the unique **set of 6 genes** that each CAThlete has: *muzzle, arms, body, tail, ears, environment.* When 2 CAThletes are bred, the offspring **may inherit traits** from one of its parents, or get a new one as a result of **mutation**. This applies to *each of the 6 genes*: **for each gene**, there is a chance of taking after one or the other parent, or having a completely new one from mutation.
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[Rainbow Eyes](https://docs.walken.io/cathletes/rainbow-eyed-cathletes) are not inherited.
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Below is the **inheritance probability per level table**, showing the percentage of possible genetic contribution of each parent as well as mutation:
| Level | 1st parent contribution | 2nd parent contribution | Mutation | Mutation Rate |
|---|
| 6 | 5% | 5% | 90% | -3 |
| 7 | 6% | 6% | 88% | -3 |
| 8 | 7% | 7% | 86% | -2 |
| 9 | 8% | 8% | 84% | -1 |
| 10 | 9% | 9% | 82% | 0 |
| 11 | 10% | 10% | 80% | 0 |
| 12 | 12.5% | 12.5% | 75% | 1 |
| 13 | 15% | 15% | 70% | 1 |
| 14 | 17,5% | 17,5% | 65% | 2 |
| 15 | 20% | 20% | 60% | 3 |
**Mutations rate.** There are **5 rarity categories** in Walken: *common, uncommon, rare, epic, legend.*
> **Mutations can downgrade the rarity of a gene (levels 6-9) or increase it (level 12 - 15).**
For **levels 6, 7, 8, 9** there is a mutation rate applied that **lowers the rarity** of the resulting genes inherited by the offspring **in case of mutation**. At **levels 10 and 11**, the rarity of the mutating genes is **not affected** by the mutation rate. *For example, the maximum rarity of genes that can be passed down to an offspring by a 6-level rare CAThlete in case of mutation would be common since the -3 mutation rate is applied.*
For **levels 12-15**, there is a mutation rate applied that **may increase the rarity of each gene** inherited by the offspring. Mind that the upgrading mutation rate does not limit the possible rarity range (like the downgrading one does); it ***gives chances to get a one-rarity higher*** (in case of level 12) or ***up to 2-rarity higher*** (level 14) gene.
*For example, if there's a rare gene for body one parent has on level 15, the offspring may get an epic or even legendary one as a result of upgrading mutation.*