Item group / breeding
The splice carrots
Carrots that add a gene to a foal. One targets a gene you have researched; the others roll one at random, either from the whole pool or from one themed slice of it.
Known Gene Splice — the targeted one
Pick the gene yourself. Craft it with a research paper for the gene you want, and feeding it to a parent gives the foal that gene.
Recipe: golden carrot + a research paper + horse hair + the rarity item for that paper’s gene — and nothing else, exactly four filled slots. The gene comes off the paper, so a rarer gene needs a rarer reagent.
The random splices refuse to hand a foal something that would kill it or cost it hearts. The Known splice does not: you named the gene and you can read what it does, so splicing a horse into a lethal genotype on purpose is allowed. Check the gene’s own page first.
Unknown Gene Splice — the random one
Recipe: golden carrot + horse hair + gunpowder. It picks one gene at random and gives the foal a random version of it. It will never pick something that kills the foal or costs it hearts — see the breeding carrots.
The five themed splices
Each is the plain Unknown Gene Splice refined with one more reagent, and each narrows the random draw to one kind of gene. Same surprise, smaller pool.
| Carrot | Recipe (shapeless) | Rolls from |
|---|---|---|
| Dilution Gene Splice | Unknown Gene Splice + light grey dye | the genes that lighten a coat |
| White Gene Splice | Unknown Gene Splice + bone meal | the white-patterning genes |
| Marking Gene Splice | Unknown Gene Splice + ink sac | the marking genes |
| Performance Gene Splice | Unknown Gene Splice + rabbit’s foot | the speed / size / jump genes |
| Magical Gene Splice | Unknown Gene Splice + amethyst shard | the invented genes |
A splice that lands marks the foal
A foal that got a gene from a splice carrot carries that fact for life, and so do its descendants — a spliced line is visibly a spliced line. The detail is on the carrot family page.
The Known Gene Splice is a custom recipe type
Not a JSON shapeless recipe: server/recipe/KnownGeneSpliceRecipe. It
requires golden carrot + a research paper +
horse hair + the rarity item for that paper’s gene, and nothing
else — exactly four filled slots. The gene is read off the paper at
craft time, so a drop-in gene file gets its carrot the moment it registers.
KnownGeneSpliceRecipe (what it requires),
SpliceRecipeDisplay (the canonical slot layout),
RarityItems (the tier → item table, deliberately off
common/), and wiki/gene-carrot/gene-carrot.js, which
redraws both for the wiki. The wiki cannot read the last two — they are
Minecraft-side — so a change there is silent on the pages until it is made
here too.
One item, many genes
known_gene_splice_carrot is one generic item
parameterised by a data component, so every gene’s carrot looks the same in the
inventory. That is a known gap.
The blacklist, and why it is derived
SpliceSafety works the random pool out from what the genes actually do
rather than from a typed list of keys: every combination the carrot could roll is
resolved through HorseTraits on an otherwise wild-type horse, and the
locus is dropped if any of them produces a condition worse than
INFORMATIONAL or leaves the horse short of baseline health. A new health
gene is excluded the moment it is registered, by having done its job. Full argument on
the carrot family page.
server/recipe/KnownGeneSpliceRecipe,
common/genetics/SpliceSafety.java.