Magical gene / lines and strokes

Zebra's Coat

Narrow transverse striping over the neck and shoulder only, standing upright on the neck and leaning back as it crosses the withers - and stopping dead at the back of the scapula.

What it can come out as

Outcome	Carrying
Zebra's Coat	`Zbc/Zbc` · `Zbc/Zbk` · `Zbc/n`
Coloured Zebra's Coat	`Zbk/Zbk`
Wild type	`Zbk/n` · `n/n`

How each one is actually drawn - region by region, and the layers it is built from - is on the coding tab.

Crossing two of them

Finding one

About 1 in 1,786 wild horses is born showing this. That is the whole of the supply: catch one, or make one with the carrot below. Breeds set their own pools and a breed built around this gene will carry it far more often than the wild population does.

Wild pair	Shows as	How often
`Zbc/Zbc`	Zebra's Coat	0.002% — 1 in 50,000
`Zbc/Zbk`	Zebra's Coat	0.008% — 1 in 12,500
`Zbc/n`	Zebra's Coat	0.038% — 1 in 2,632
`Zbk/Zbk`	Coloured Zebra's Coat	0.008% — 1 in 12,500
`n/n`	Wild type	99.944%

Its gene carrot

The file

common/src/main/resources/horsegenetics/genes/zebras_coat.json — a data-driven gene, not a Java class. It is listed in the index.json beside it and registered by Genes' class initialiser at startup.

Key	`horsegenetics.zebras_coat`
Phase	magical — it adds signed colour in phase 3, after the pigment has resolved
Priority	361 — where it sits in the one `(priority, key)` paint order
Alleles	`Zbc` · `Zbk` · `n`
Varies per horse	4 values drawn once off the expressing allele copy, so a foal that inherits the copy inherits the look
Built from	AXIS, STROKES, TOWARD

What it paints

Each outcome, described the way the gene file describes it, and then the layers that draw it in the order they are painted. The prose is the part a reader checks a bake against; the list underneath is what the engine actually did.

Zebra's Coat

Ten to thirty narrow stripes with tapered ends - a hairline pen, not a brush - crossing the neck square and then swinging back and curving as the field passes the withers and shoulder. Roughly a fifth of them split into two branches near their lower end. Nothing behind the scapula and nothing on the legs: the sharpness of that cut-off is the marking's signature.

upright stripes down the neck — STROKES, painted with TOWARD
the same stripes leaning back over the shoulder — STROKES × AXIS, painted with TOWARD
a few reaching up onto the poll — STROKES × AXIS, painted with TOWARD

Coloured Zebra's Coat

The same marking in a colour the line carries rather than in white. Fully recessive: it takes two copies, and a single copy beside the white allele shows white. It never gives blue eyes, whatever the white form does.

upright stripes down the neck, in colour — STROKES, painted with TOWARD
the same stripes leaning back over the shoulder, in colour — STROKES × AXIS, painted with TOWARD
a few reaching up onto the poll, in colour — STROKES × AXIS, painted with TOWARD

Wild type

No striping.

Paints nothing.