- The chances of one mutation for 2 dinos, both of whose mutation counter is below 20, are 7.31%.
- There can be a total of 3 new mutations on an offspring.
- These chances are reduced by 45% or 55% (depending on which parent has the higher stat) if one of the parents has its mutation counter above 20.
- The chances are reduced by 55% if the total counter value of the parent with the higher stat value (of the stat that is to be mutated) is above 20, or 45% if the counter of the parent with the lower stat value is above 20.
- There is no chance of a mutation if both parents have their mutation counter above 20.
- A mutation can be in any stat, and each mutation adds 2 wild points to that stat.
- Note: because speed gets no increase from wild points, it is effectively a "wasted mutation" as a mutation in speed causes no change to the stat itself, only the counter.
- The mutation counter is NOT an accurate representation of the number of mutations on a creature.
- The total counter value that a parent passes down to a baby is the sum of its paternal and maternal counter values.
- So, a baby's paternal counter value is its father's total counter value, and maternal counter value is its mother’s total counter value.
- If a baby gets a mutation(s), then either the maternal or paternal counter value is increased by one for each mutation (not related to which parent the stat with the mutation was inherited from).
- So, if a father has a paternal counter value of 10 and its maternal counter value is 5, then in total it has 15 mutations (10+5). If it then has an offspring/child with a mutation from its paternal side, then the offspring's paternal counter value will be 16 (10+5+1).
Probability of Mutation
For each offspring up to three mutations can occur, each with a 2.5% chance, assuming both parents are eligible to receive a mutation. If multiple mutations occur, they may affect the same or different stats.
The probability for at least one mutation in an offspring whose parents both have less than 20 matrilineal and patrilineal mutations is 7.31%, for at least two mutations it is 0.184%, and for three mutations the probability is 0.00156%.
The probability for at least one mutation when the parent that provides the improved stat has 20 mutations or higher is 4.07% because the game prefers the "weaker" of both parents to provide the mutation increase in the ancestry by 55%.
The probability for at least one mutation in an offspring whose "worse stat" parent has 20 or more mutations is 3.337%. because the game prefers the "weaker" parent as the carrier of the mutation increase in the ancestry. Since the "weaker" parent is already above 20 mutations, the game disregards the mutation. This will end in a lower mutation probability than the previous case. This scenario will not happen in the normal game flow since the parent that carries the mutated stat will usually be the one whose stat is higher.
The probability for at least one mutation in an offspring whose parents each have more than 20 mutations is 0%.
Stat mutations are determined and applied in the following steps (from the code at ):
- Initial stat selection from parents (not technically part of mutations)
- Select a stat for mutation
- Assign a parent as source of potential mutation
- Random roll for mutation (2.5% chance)
- Apply mutation and color change
- Repeat #2-5 two more times
Many write-ups regarding mutations will mention "mutating a stat on a parent" or similar language, which may be confusing if you are new to breeding. To be clear, only the offspring's stats are ever actually modified/mutated, after they are initially set in step #1 above. The mutation mechanic assigns one of the parents as the source of a mutation, but it is not actually mutating the parent creature.
When you read "parent has 20/20" or similar below, this is referring to the total mutations on the parent - its Matrilineal+Patrilineal mutation Counters. See the Mutation Counters section for more details and also the code at.
1. Initial Stat Selection from Parents
The initial stat values are selected from either the mother or the father, with a 55% chance that the stronger stat will be selected. For example if the mother has 20 wild levels in melee and the father has 30 levels, it is 55% likely that the offspring's melee value will initially (before mutations) be set at +30 levels.
2. Selecting a Stat for Mutation
(This step along with the next three are repeated for three iterations.)
A single stat is selected for possible Mutation. Only stats which can be leveled up for the species will be selected.
3. Assigning a Parent as Source of Mutation
One of the parents is chosen as the source of the mutation, this is based on the stat picked from the parent, with a 55% chance that the weaker parent (in that stat) is chosen. This is a completely independent check from the initial stat assignment, meaning that the father might have provided the offspring's initial melee stat, but the mother is the source of a mutation to it.
If the source of the mutation has reached the 20 mutation limit, then this mutation chance is lost and a new iteration (if any are left) begins at #2. This means that the combined number of mutations for either the father or the mother must be <20, because the check is performed with the baby's mutation counter (see next section).
For example, if you breed a 20/20 father and a 0/20 mother and on mutation iteration #1 (of 3) the father is chosen as the source for a mutation, the mutation does not happen (the 2.5% chance is not even evaluated) and the iteration is complete. This of course reduces (by approximately 50%) the already-slim chances of a mutation actually occurring so if you want the full 7.31% chance of at least one mutation, both parents must be <20. See the section below on mutation Stacking for more information about breeding maximum stats.
4. Random Roll for Mutation
If the "source" parent is valid, then the 2.5% chance is evaluated. If this check fails, this mutation iteration is complete and a new iteration (if any are left) begins at #2.
5. Apply Mutation and Color Change
If the mutation check succeeds, then the offspring's stat is evaluated; if it's determined less than 255 levels it is then given 2 wild levels and the mutation counter on the side (Matrilineal/Patrilineal) of the source of the mutation (not the source of the initial stat) is increased by 1. Additionally, a random mutation to a color region will occur. This color mutation may not be obvious due to it resulting in a very similar color to one of the parents, or due to the algorithm choosing a color region not used by the species.
Any color (including dyes) can be selected for the resulting color mutation, with around a 10% chance to select a dye and 90% chance to select a normal color. Also note that the invalid color IDs 0 and 227 can rarely be rolled. ID 0 shows only the creature base texture, while ID 227 shows as white.
6. Repeat #2-5 Twice More
Regardless of whether or not a mutation occurred, the process is repeated twice more. The same stat may be affected twice (+4) or even three times (+6) if you are especially lucky!
The Ancestry screen for each creature shows a mutation counter on both the Matrilineal (mother's) and Patrilineal (father's) side. These numbers do not show the actual mutations on the creature. Rather, they are a combination of the parents' mutation counters plus any actual mutations expressed when the baby was hatched. Without knowing details of the ancestry of a particular creature, it is impossible to tell how many actual mutations have been a) carried forward from a parent or b) expressed at birth (though with some reverse-engineering it is possible to make some guesses). The reason the numbers are given as X/20 is explained below.
Wild creatures begin with zero mutations on both sides. Baby tame creatures (from breeding, not from stolen eggs e.g. Wyvern) inherit a base mutation counter value from each parent. This base value is equal to the parent's own matrilineal + patrilineal counters.
- mother's Matrilineal + mother's Patrilineal = baby's Matrilineal counter
- father's Matrilineal + father's Patrilineal = baby's Patrilineal counter
Additionally, if Step 4 above results in a mutation on a baby's stat, the mutation counter for the source of the mutation is increased. If mother was the source of the mutation (not necessarily the source of the initial stat), the Matrilineal counter gets +1. If the father was the source of the mutation, then baby's Patrilineal counter gets +1.
When considering creatures as potential parents, if the creature's combined mutation counters (Matrilineal + Patrilineal) is greater than 20, then any potential mutations which have that parent as the source (Step 3 above) will automatically fail.
Here is an example showing some possible mutation counter results for Mutated and non-Mutated babies:
|Baby 1||5||15||0||No successful mutations; baby inherits M+P counters from each side|
|Baby 2||5||16||1 (+2 levels to a stat)||Father was the source of the mutation; +1 to P counter|
|Baby 3||6||15||1 (+2 levels to a stat)||Mother was the source of the mutation; +1 to M counter|
|Baby 4||6||16||2 (+2 levels to 2 stats/+4 to one stat)||Both parents were the source of a mutation; +1 to both M & P counters|
Because the mutation count is stored as a signed 32-bit integer it's possible that mutation counters will be expressed as a negative number. This happens when the count would have exceeded 2,147,483,647. The signing bit is then reversed and a negative number is observed. The inverse is also true, when two extremely small numbers are added together and exceed -2,147,483,648 the signing bit will flip producing a positive number. For all intents and purposes these negative numbers are still less than the maximum of 20, therefore a male with a negative mutation count can be bred with a female with a < 20 mutation count and be eligible for the 7.31% chance of a mutation occurring.
How to Breed Super Creatures
Selective mutation breeding / mutation stacking
Note: The goal of this process is to obtain a level 449 creature that has NO levels in any stat except the ones you explicitly want. That's why we're starting with a level one-ish dino in step 2.
- Breed a creature that has the best stats that you can find. – the creature has to have less than a combined mutation counter of 20
- Get a low level creature that has 0 levels in each of the stats you aren't interested in, e.g. Oxygen, Food, Weight, and Speed. All creatures are limited on Official Servers to level 449 or less so every level counts.
- Get a breeding pair of 1 male and as many females as you can (the more the faster the whole process gets) all with equal stats to the creature from step 1 with the best desired stats. Ideally, they (especially the females) should all have the same stats and 0 on their combined mutation counters.
- Breed… a lot.
- Get a mutation in the stat you are looking for (e.g. Health)
- on a baby that inherited the lower stat of both parents
- on a baby that inherited the higher stat of both parents
- Breed your new mutation to a male creature.
- Swap your original male from step 3 with the new mutated (e.g. Health) male creature.
- Repeat point 5.2 - 7.
- Stop far before reaching level 450, and level 500 for x- and r- creatures. – The Official Server common creature level cap is level 450, and 500 for x- and r- creatures (Voidwyrm included). Any creature that reaches those levels will be not able to level up. You should get a stop many levels before those limits, especially considering how a the stats value can rise on level ups. Actual level up limit on Official servers is 88; you may want to stop before that value (like 73 levels), since getting the last level ups with experience points may be difficult, especially on non-boss fights designated creatures. If you intend to take advantage of all possible 88 level ups, you may want to target level 362, and 412 for x- and -r creatures.
- Stop if you reach 253 or 254 levels in specific stat – Ark will prevent a stat from being levelled if the wild level count for that stat is 255 but not if it is lower and not if the stat's wild levels plus the stat's domestic levels meet or exceed 255.
Note: The male creature's mutation counter will exceed 20. This isn't an issue as long as you continue to use females with a combined mutation counter less than 20. The male's will continue to contribute their high stat levels while the females will continue to offer mutation chances.
Example: Breeding a god Rex.
- Starting Rex stats bred from all best Rex's you have.
- Getting a level 1 Rex. (May require taming a few low level Rex's and breeding them together to get 0's in all of the stats)
- Breeding a Rex that has no points in undesirable stats, e.g. Oxygen, Food, Weight, and Speed.
- Selective mutations breeding – for a very long time
- In this case the goal was to get high levels for health and melee, so every health or melee mutation was used.
- Final stats
- Breeding for color – such an OP creature needs to look nice too
Every new color mutation that appeared in the process was kept, so in the end there were around 200+ Rex's of every color imaginable on each color region.
The Rex in the example was bred a little different, all levels in movement speed were eliminated in the end.
- Why did my baby creature get +2 levels in a stat, but the colors seem to be the same?
- The color mutation can target any of the six color regions, however not all creatures use all regions, so it is possible that the color mutation is invisible. For example, if color regions 1, 2, or 3 are targeted for mutation on a Sabertooth, you will not see any visible color change.
- Another reason for not seeing a color mutation is that the mutated color is the same or very similar to the original color.
- Why did my baby creature get a color mutation, but no visible stat mutation?
- Either a) the stat mutation targeted Movement Speed, which will not result in a visible increase in the stat value or b) the source of the base stat was the weaker parent, who was exactly two wild levels below its mate and so, after mutation, the baby ends up with exactly the same stat levels as the stronger parent. It looks to you like the baby just inherited from the stronger parent when it actually has [weaker parent +2].
- Note that a stat mutation is always detectable through a higher Torpor value and higher total level. That is, if you see that Torpor & total level are higher than expected, it is certain that a stat mutation occurred even if it is not obvious.
- Why did total level go up, but there is no visible stat increase and no color change?
- This can happen as a combination of the first two cases. The only thing that visibly changes is the Torpor and the total level.
- Can the mutated color be the same as the original color?
- Yes, the mutation color is chosen randomly.
- Can a creature mutate twice at the same time?
- Yes, up to three mutations can happen for an offspring, with +2 wild levels on a stat one color change for each mutation. Multiple mutations can target the same stat, so you could see +4 or +6 wild levels on a single stat.
- Can creatures be bred infinitely to increase their stats?
- No, there is a level cap of 450 on official servers. Any tamed/bred dinos that reach levels above 450 on birth are deleted by the game after server restart and once you hit the 450 Levels on your adult dino you won't be able to level your creature anymore. Note that selective mutation breeding is a very long process and it’s going to take months of real time, until that limit is hit. Keep this in mind that the level cap ONLY applies to Official Servers and both Singleplayer and Unofficial aren't affected by level caps. (Unless they set one up themeselves)
- Could a low level creature with 3 mutation in a stat used to transfer these mutations on a high level creature to increase its stat-values?
- No, mutations cannot be transferred to other creatures. Only offspring can get new mutations. As well, the game does not record which stats on a creature are mutated or by how much. Once the mutation algorithm is finished and the baby is hatched/born, the only data recorded is the current levels in each stat and the total Matrilineal and Patrilineal mutation counters. The game does not record whether the current stat levels are naturally inherited or mutated.
- Can the offspring of parents with total mutations (Matrilineal + Patrilineal) of greater than 20 have mutations?
- No, at least one parent with a total mutation counter of less than 20 is needed to have an offspring with a mutation. If only one parent meets this requirement, the chance for a mutation is approximately halved..
- Can the offspring of a parent with more than 20 total mutations have inherit a stat of this parent and have a mutation on this stat?
- Yes, if the other parent has a mutation counter of less than 20. This method is used in selective mutation breeding. See the detailed mechanics above regarding the source of the initial stat vs. the source of the mutation. Either parent can be the source of the initial stat, but only a <20 parent can be the source of a mutation.
- Does a high mutation counter imply a good creature?
- No. The mutation counter doesn't reflect the stats of the creature and is independent of them, so a creature with 0 mutations can have very high levels and a creature with a high mutation-counter can have 0 levels in each stat. For more information watch one of tagbacktv’s videos on mutations.
External Video Tutorial
- Mutation probabilities explored (includes JSON data) by mgxts on Reddit
- Mutations and You - A Guide on Breeding Mutations by daymeeuhn on Reddit
- Mutation-probability on reddit
- This was verified by admin spawning a creature and checking it's stat levels with the Admin Rifle. The raptor had 252 melee and 255 speed. Speed levelup was disabled in the creature's inventory, but melee was leveled an additional 11 times without issue.
- mutations and you on reddit