Inbreeding Risks

If duplicated ancestors exist between the parents, offspring will receive a chance to receive penalty mutations. While roughly based on the real-life way of predicting problems from shared ancestors, the math is much simplified- basically, a way to track a chance for penalties. 

When two dergons with a shared individual in their lineage are bred, their offspring will have an inbreeding coefficient (Coi) present in their Health field. This is calculated by adding a set number for the positions of the duplicated ancestor, and will be passed down with the dergon's offspring with the same generational degradation as CoAs and CoRs: the parents' Coi are added, then halved and rounded up. 

Dergons are assumed to have a Coi of zero unless it’s noted on their import! It will go under Health, and look like Inbred ( Coi 0.25). This number in parentheses is the chance (out of 1.00) that dergon has to receive mutations. Usually, a dergon will have a Coi of between 0 and .5, with a coi of .5 giving a 50% chance of mutation. 

Offspring of dergons with Cois will have a chance to receive a penalty, mutation, and/or infertility, that chance being based on the parents’ Cois added, then halved. For instance, dergons with coi .04 and coi .05 would add to .09, then halve to .05, and the offspring’s chance for mutation would be 5%. A dergon with a Coi of .08 and a dergon of Coi 0 ‘s offspring would have a Coi of .04, and a 4% chance for penalty. If an offspring's Coi would be .01 or under, it vanishes and the dergon is no longer considered inbred. 

Penalties are rolled with the same chance of occurring as their Coi, and can be Mild, Moderate, or Severe depending on the Coi's strength. 

When determining inbreeding, dergons' genetics are considered up to what will be visible on the offspring's lineage- up to the grandparents of the dergons paired together. 

The value of the Coi is determined by the positions of the duplicated ancestors, with further back positions being less severe.

  _______________________________ Position 3
____________ Position 2
______________________________ Position 3
Position 1 (Parent 1)
______________________________ Position 3
____________ Position 2
______________________________ Position 3

  ______________________________ Position 3
____________ Position 2
______________________________ Position 3
Position 1 (Parent 2)
______________________________ Position 3
____________ Position 2
______________________________ Position 3

Here are the possible ancestor duplications, with the corresponding Coi that offspring will inherit: 

Position 3/Position 3
Shared great-grandparents
Coi 0.15 

Position 3/Position 2
Shared grandparent/great-grandparent
Coi 0.2

Position 2/Position 2
Shared grandparents
Coi 0.25

Position 3/Position 1
Shared parent/great-grandparent
Coi 0.3

Position 2/Position 1
Shared parent/grandparent
Coi 0.35

These are the values between ancestors from Parent 1 to Parent 2! If any ancestors are duplicated within a single parent's line, they will already have a Coi assigned, and the ancestors which created the parent's Coi will be disregarded. Any chances from duplicated ancestors will be added together in the calculation- for instance, if a dergon would have both a shared grandparent and shared great-grandparent in their lineage, they would receive both the .25 and .15 for those ancestors, resulting in a final Coi of .4.

If one parent has a Coi and is bred to another, with whom they share ancestors, the hatchlings will receive both that parent's Coi and an additional Coi calculation from the new instance of inbreeding. 

For instance, this lineage:

  _______________________________ Dergon A
____________ Position 2
______________________________ Position 3
Parent 1 (Coi .15)
______________________________ Position 3
____________ Position 2
______________________________ Position 3

  ______________________________ Position 3
____________ Dergon A
______________________________ Position 3
Parent 2 (Coi 0)
______________________________ Position 3
____________ Position 2
______________________________ Position 3

Would result in offspring inheriting a Coi of .08 from Parent 1, as well as a Coi of .20 from the new instance of a shared ancestor in Dergon A. This would mean that hatchlings have a Coi of .28.  

A dergon's Coi, translated into a percentage of 1, determines the chance for a dergon to receive a penalty or infertility, as seen below:
1 = 100%
0.5 = 50%
0.01 = 1%

Penalties and Infertility are rolled for separately, meaning a dergon may be infertile as well as being given a separate penalty. 

Mild penalties/Mutations

• Infertility: Genetic strength starts at Low; Clutch size is 1-3; Eggs have a 30% chance to be a dud.

• Reduced Genes: All Marking, Modifier, and Vibrant genes have a 50% chance to be removed from the geno.

• Oblivious: Has a lower chance to bring back items from activities. (Can also be Moderate or Severe)

• Repugnant: Does not give or receive the Other Dergon AEX bonus when drawn with other imports. 

• Mild Strange or Missing Features

Moderate penalties

• Sterility: Genetic strength starts at Weak; Clutch size is 0-2; Eggs have a 50% chance to be a dud.

• Low Genes: Genetic strength is locked to Low permanently.

• Slow Training: An extra activity submission is needed to level up their Skills. (Can also be Severe)

• Plain Genes: All Marking, Modifier, and Vibrant genes are removed from the geno, leaving only a Natural base color.

• Carrying Color Mutation

Severe penalties

• Stillborn: Geno cannot be uploaded as an import without magical intervention.

• Weak Genes: Genetic strength is locked to Weak permanently.

• Basic Training: Skills cannot be leveled up.

• Clumsy: Can only bring back item stacks of 1 from activities.

• Stunted Wings: Can only complete an Aerial Display after ranking up at least once.