Magical gene / no coat effect
Spontaneous breeding
Two of these horses in a field will breed without being asked, and without being fed anything. It takes two — one expressing horse and an ordinary one does nothing at all.
The gene, its inheritance and its founder table exist and are covered by the test suite; the translator that turns it into behaviour was written against the 26.1.2 sources and is flagged unverified in its own comments. Nothing on this page has been watched happening to a horse. What to look at, and what is most likely to be wrong, is on To be verified.
What it does
| Combination | Outcome |
|---|---|
Spb/Spb, with another Spb/Spb nearby | they breed on their own, on a long cycle |
Spb/Spb alone | nothing — it needs a partner that also expresses |
| anything else | nothing |
You will not find one
Wild horses carry it and never express it. Two carriers must meet, and one foal in four of that cross expresses — and then that foal needs another one like it before anything happens. This is a deliberate breeding project, not a discovery, and the gene database is the only practical way to hunt it.
Health
None. The risk is to your pasture, not to the horse.
- Gene key
horsegenetics.spontaneous_breeding- Alleles
Spbspontaneous,n- Inheritance
- homozygous recessive; carriers in the wild, never homozygous founders
- Reaches the game as
- a breeding-system hook, not an
effectsverb - Coat effect
- none, ever
Uncapped automatic animal breeding is the classic way to kill a server, and this one runs while the player is asleep and not watching. A local population cap and a cooldown are not polish — they are the first thing to build, before the gene does anything at all. Count horses in radius, stop at a ceiling, and honour the ordinary breeding cooldown on top.
Everything the normal breeding path checks — age, cooldown, the mod’s own pedigree and stat inheritance — must still run. This gene decides whether the pair is willing; it must not become a second breeding implementation.
Every verb in AbilityType is something the horse does on a tick. This is something the breeding system asks about, the way DietContribution is asked about food. Building it as an effect would put breeding logic in the ability translator, where nothing else about breeding lives.
Why it takes two
A single expressing horse that bred with anything would spread itself through a herd in a few generations and stop being rare. Requiring both parents to express makes the trait self-limiting genetically as well as mechanically: the population of spontaneous breeders can only grow where somebody has already gathered two.
A gene the testing layer exists for
Invisible in the wild, invisible in a carrier, and only observable once you have already succeeded. That makes it close to unfindable by looking — which is the point. The gene database and the research papers are the intended route, and this locus is one of the clearest arguments for their existing at all.
common/genetics/genes/SpontaneousBreedingGene.java