The Isle Mutations and Entombing Explained
Mutations are the only permanent progression in The Isle, and entombing is how you carry them past a single life. The system has changed several times since it reached Evrima in 2024, which is why guides disagree with each other and with the game. This page follows the developers' own patch notes and dev blogs, says which build each fact comes from, and finishes with the server side: what an operator can enable, disable or tune.
Mutations in one life
- You unlock them by how you live. Since the March 2024 redesign the "lifecycle" and "lifestyle" mutations are one system: what you do during a life unlocks mutations, and an unlocked mutation can then be chosen at the life stages that follow.
- Four picks, and they are permanent. The developers designed around a player selecting four mutations in one life, and a selected mutation locks in for that life. Choose the weak one for the wrong reason and you keep it.
- They stopped touching speed. Since the October 2025 balance pass no mutation increases player speed, and some mutations are no longer inheritable when the offspring could not use them.
- Nesting mutations are the exception to inheritance. Sequential Hermaphroditism (change sex once) and Parthenogenesis (a female nests without a mate) are non-inheritable by design.
Entombing: what 100% growth unlocks
Entombing arrived with the Elder life stage in patch 0.21.321 (December 2025). At 100% growth you become eligible to entomb. Your current animal's life ends, you start again as a juvenile of the same species, and the mutations from the previous life come with you, with their benefits enhanced. Each time you repeat the cycle they scale up again, until they reach a cap the developers have not published as a number. An Elder can also pick a fourth mutation before entombing.
| Generation | What you start with | Source |
|---|---|---|
| Gen 1 | No mutations. Up to four unlocked and chosen during the life. | DevBlog #45, March 2024 |
| Gen 2 and later | Everything chosen in the previous generation, stronger than before, plus new picks during this life. | Patch 0.21.321; DevBlog #61 |
| Egg-born with two Prime parents | Mutations inherited from both parents, as reported by players who tested it in September 2026. | Community testing, not a developer statement |
| Cap | Community charts published in September 2026 count four entombs and sixteen mutations across a lineage. The developers confirm a cap exists and have not stated the figure. | Community chart; DevBlog #61 |
Two practical consequences players discover the hard way. A third-generation animal is noticeably tougher than a first-generation one with the same picks, which is the strengthening at work, so a lineage is worth protecting. And the game has had bugs around entombing since it shipped, including skins resetting and sex swapping (DevBlog #65, November 2025), so an animal that came back different is a known problem to report, not something you did.
Entomb Save is not on the public branch yet. DevBlog #71 (August 2026) describes a stored character after entombing, so you can keep a lineage without playing that species next, with the rule that entombing the same species again overwrites it after a warning. DevBlog #72 (September 2026) has it in final testing for the hordetest branch. Until it reaches the Evrima public branch, entombing still means playing the same species next. If an unofficial server claims to have it, they are on hordetest, and your client must be too.
What the server controls
An operator can turn mutations off, or enable a specific list with tuned values. The keys below are the ones the developers published in their patch notes for server owners and the current server build reads them; both belong in the [/Script/TheIsle.TIGameSession] section described in the Game.ini configuration guide.
[/Script/TheIsle.TIGameSession]
bEnableMutations=true
EnabledMutations=(MutationName="Hemomania",EffectValue=0.05)
EnabledMutations=(MutationName="Hematophagy",EffectValue=0.25)bEnableMutations=falseremoves the system entirely. Players on such a server never see the mutation screen, and entombing gives them nothing to carry forward.EnabledMutationsis opt-in, all or nothing: the moment you list one mutation, only the listed ones exist on that server, so a server that wants "everything except one" has to list everything else with its default value.- The growth multiplier decides how long a life takes to reach the 100% needed to entomb, so it is the setting that most changes how quickly a lineage builds. Servers advertising "1x" or "3x" growth are describing it; see choosing an unofficial server for how that plays out.
- Per-player mutation and growth data lives in the server's save, so backups are what protect a community's lineages, not the config file.
The developers' notes quoted here are on the official The Isle news feed, where each patch and dev blog is dated. The Game.ini Generator writes a complete server file with mutations on or off.
Host The Isle Evrima with Supercraft to run mutations the way your group wants them, with the save backed up so no lineage is lost to a bad update.