Magical gene / an emission, no coat effect

Molten hooves

Hoofprints lie on the ground behind the horse as it moves, and fade as they cool. Four kinds: white, black, one colour, or several. The colours are written on the allele copy and inherited with it, so a line breeds true to its own fire. It is light and particles only — nothing it runs over catches.

What it does

Combination	Outcome
`MltW` with anything	white glowing prints — one copy is enough
`MltB/MltB`	black prints that do not glow — a scorch, not an ember
`MltC/MltC`	glowing prints in one colour
`MltM/MltM`	glowing prints running through several colours
any other mix, e.g. `MltB/n` or `MltC/MltM`	nothing — a carrier

White is dominant over everything, so it is the one you can simply catch. The other three are recessive: each shows only when a horse has two copies of the same one, which makes a black- or a multicolour-hooved line something you have to breed for. The colour and multicolour prints take their colours from the alleles; white is always white and black always black.

It does not set anything on fire

Worth saying plainly, because the name promises otherwise. Each print lies flat, glows in the dark for about four seconds and fades; it does not light up the ground around it. Grass, crops, wooden stables and the horse itself are all safe, and you can ride one through a forest.

Health

None. It costs the horse nothing and protects it from nothing.

Gene key: horsegenetics.molten_hooves
Alleles: MltW white, MltB black, MltC colour, MltM multicolour, n
Priority: 154 — beside the other emission loci; it paints nothing, so the number is a slot
Inheritance: white dominant over all; black, colour and multicolour recessive, each expressing only as its own homozygote
Reaches the game as: one emitter (white, black, colour) or two, one per copy (multicolour); the emitter’s data is 1 for a glowing print and 0 for black’s unlit one
Particle: horsegenetics:hoofprint — the mod’s own, laid by stride
Epigenetic: two colours per allele copy — read by the colour allele (copy one’s first) and the multicolour allele (all four)
Wild founders: white 2% one copy, 0.2% two; black 0.3%, colour 0.5%, multicolour 0.2% as homozygotes — no invisible carriers
Coat effect: none, ever

Prints seen in game; the four alleles are not yet

The owner has seen the prints render (2026-09-10). The same day the single dominant Mlt became four alleles - a dominant white and three recessive colours - which is covered by MoltenHoovesGeneTest and not yet played. Checklist on To be verified.

It needed one piece of new machinery: its own particle

Still no verb, trigger or condition flag — an emitter anchored at hooves with an epigenetic colour, as particle and rainbow dust do. But the emitter names horsegenetics:hoofprint (particle/ModParticles, particle/HoofprintOptions, client/HoofprintParticle, the sprite at textures/particle/hoofprint.png), and GeneAbilityHandler pulls any emitter naming it out of the ordinary path into layHoofprint: one print each time the horse covers half a block (scaled by its size), hooves in trot order, snapped to the top of whatever is under that hoof, skipped over air and fluid. A multicolour horse’s two emitters take turns print by print, and HoofprintOptions.glow (from the emitter’s data) is what lets black’s prints be lit by the world instead of glowing. The emitter’s count and chance are not used on this path. The particle is not in the gene file format’s vocabulary, so only this built-in gene can name it.

White is dominant, so the particle budget matters more here than anywhere else

Every other emitter locus in the mod is recessive or rare. White expresses on a single copy, so a populated stable can have a dozen horses all printing at once. The cost is bounded by distance rather than time — one print per half-block walked, each living eighty ticks — so a standing herd costs nothing. The fix for “not dramatic enough” is a brighter colour or a longer life, not a shorter stride.

Real fire was considered and rejected

The first specification placed actual fire blocks. On a dominant gene that burns down the stable, the forest and the horse. If a later session wants the mechanic back, it must come with a demotion to recessive — the two decisions are one decision.

Why it has its own particle

No vanilla particle is coloured, glowing and flat. Flame glows but ignores colour, and a colour written on the allele copy is the entire point of the locus. Dust takes a colour — the first build used dust_color_transition, the same particle rainbow dust uses — but it is lit by the world, faces the camera, and scatters, so in play it read as coloured puffs rather than prints. The owner asked for marks on the ground. The print is a flat quad drawn at a fixed rotation (vanilla’s shriek particle is the precedent), held at full block light so it glows, turned to the heading the horse was travelling, and fading from the copy’s first colour to its second.

A molten horse may burn blue

The hue is unconstrained. EpiValue.colour bounds saturation and value but rolls hue over the whole circle, and rather than add a hue-bounded draw for one gene the locus simply allows it. Nothing about molten hooves needs to be orange, and a line that breeds true to a cold blue fire is a better outcome than a fourth kind of colour draw.

Where the colour lives

On the allele copy, not on the horse. Two molten copies carry two colours and the trail draws from both, which is why a heterozygote and a homozygote look different even though the gene is dominant and the behaviour is identical. That is the same arrangement particle uses, and reusing it means the epigenetic drift on breeding already works with no extra code.

Why dominant, when almost nothing else is

The magical emission loci are nearly all recessive, which makes them a reward for breeding and invisible until you get there. One of them ought not to be. A dominant emission gene spreads through a herd on its own, so a player who catches a single molten horse and crosses it into their line sees the result immediately — and that is a different kind of pleasure from the long recessive hunt, worth having once.

A cosmetic gene that admits it

The mod has a standing problem with genes that promise a mechanic and deliver a look. This one is a look on purpose and says so on the first tab, which is cheaper and more honest than a fire mechanic nobody dares breed.

Particle Rainbow dust The effects block What to check in-game

Planned source: common/genetics/genes/MoltenHoovesGene.java