Every species has a hidden number called breeding power (internally CombiRank — you can see it for every pal in the Paldex tab). When two different species breed:

target = floor((powerA + powerB + 1) ÷ 2)

The child is the species whose breeding power is closest to that target. If two species are exactly equally close, a hidden priority value decides the winner. That's it — the whole species system is one averaging formula. See breeding power in the Paldex

• Not every pal can be a "math result": legendaries and all sub-species (Relaxaurus Lux, Incineram Noct, etc.) are excluded from the pool — only 183 of the 288 species can hatch from averaging. The excluded ones need their unique recipe or same-species parents.
• Unique recipes override the math. This app checks them first, exactly like the game.
• A handful of recipes are gender-dependent: Katress ♀ × Wixen ♂ gives Katress Ignis, but Katress ♂ × Wixen ♀ gives Wixen Noct. The Breed tab shows both outcomes when it matters.
• Because it's an average, you can often reach the same child from hundreds of different pairs — that's what the Find Parents tab enumerates. Open Find Parents

Since 1.0 the cake you feed the farm changes what hatches. Pick it per goal:

• Cake — the baseline. One egg, normal odds (recipe above).
• Mushroom Cake · Tech 30 — slightly better stat (IV) rolls on the child.
  5× Flour5× Mushrooms3× Cavern Mushrooms8× Eggs2× Honey
• Vegetable Cake · Tech 47 — two eggs per breeding cycle. Doubles throughput, and each egg rolls its mutation chance separately.
  8× Flour8× Tomatoes7× Lettuce8× Eggs4× Honey
• Extravagant Vegetable Cake · Tech 60 — mutation chance rises to ~3% per egg, plus better stat rolls. The mutation-hunting pick.
  12× Flour8× Cotton Candy10× Potatoes6× Onions8× Carrots
• Special Cake · Tech 74 — much better odds that the child inherits the parents' passives. With clean parents carrying exactly the 4 passives you want, keepers become common. No effect on mutation or egg count.
  20× Flour8× Caramel Cotton Candy15× Milk15× Eggs2× Mammorest Meat

The child can inherit up to 4 passive skills drawn from the combined pool of both parents' passives, and it can also roll random passives that neither parent has.

• Roughly speaking (community-measured, the game doesn't show the odds): if the parents together have exactly the 4 passives you want and nothing else, about 1 in 10 eggs is a perfect 4/4 baby.
• Every junk passive on either parent dilutes the pool and tanks your odds. The meta strategy is to breed "clean" parents first: pals whose only passives are ones you want.
• Classic workflow: combine 2 desired passives on one parent, 2 on the other → hatch until a child has 3–4 → use that child as a new parent. Passives have no gender, so any keeper can pair with any opposite-gender partner of the right species chain.
• Popular combat set: Legend (from legendaries — yes, it inherits!), Musclehead, Ferocious, element +20%. Work set: Artisan, Serious, Lucky, Work Slave.
• Endgame: the Special Cake (Tech 74) sharply raises how much of the parents' pool carries over. The odds shown in this app assume a regular Cake — treat them as a floor once you're baking Special Cakes.
• Which passives are worth the effort — and which 15 are worth breeding out — is the Skills tab, with every effect in numbers. Browse every passive

• Each pal has hidden IVs (0–100) for HP, Attack and Defense — worth roughly +30% to a stat at max. Community testing says each stat usually copies one parent's value, at least one stat always comes from a parent, and the rest can roll fresh — so hatch several keepers and compare. A Mushroom or Extravagant Vegetable Cake nudges the rolls upward.
• Active skills (changed in 1.0): the child's inherited attack skills are drawn from the three skills equipped on the parents at breeding time — set both parents' movesets before dropping them in the farm.
• Gender is rolled per species — every pal card in this app shows the ♂/♀ odds. Some species are heavily skewed (useful to know when you need a specific gender for a gender-locked recipe or your next pairing).
• Alpha (oversized) status does not inherit; the Lucky passive from lucky pals inherits like any other passive.

• Every bred egg has a ~1% chance to mutate — ~3% if you use an Extravagant Vegetable Cake instead of a regular Cake. A Vegetable Cake's two eggs each roll separately, so it's ≈2% per breeding cycle at the base rate.
• Mutated eggs are visibly different — purple with a distinct pattern — so you'll know before it hatches.
• A mutated pal can come with any of: up to 2 free condensation levels, Alpha (oversized) status, one or more mutation-exclusive passives, or even hatch as a different species than the normal child.
• The exclusive passives (marked 🧬 in this app's passive picker) can't be rolled any other way: Babysitter (+30% egg production & incubation speed at base — the breeding meta pick), Idiosyncratic, Immortality, Heavily Armored, Skymarcher. Once obtained they inherit like normal passives.
• Which species a mutated egg can turn into is not fully understood yet — community data collection is ongoing, so this app doesn't pretend to predict it. Treat species mutations as a lottery bonus.

• Egg type and size depend on the child (element + rarity). Bigger/rarer eggs take longer — huge eggs can take many real-time hours at default settings.
• Eggs have a temperature preference ("feels a little cold…"). Match it — put the incubator near a heater or campfire for warm-loving eggs, a cooler for cold-loving ones — and incubation speeds up significantly.
• 1.0 halved default incubation times in newly created Normal and Hard worlds — existing saves keep whatever they had. The world setting PalEggDefaultHatchingTime still scales everything; many servers set it to 0–2 h.
• One farm produces one egg per cake per ~5 minutes while both parents are assigned and fed (two eggs with a Vegetable Cake). Build multiple breeding farms to parallelize.
• Cakes stored in the breeding farm's chest never spoil — stock it up.
• True endgame: the Ancient Breeding Facility (Tech 76 · 100× Pal Metal Ingot, 50× AI Core, 30× Ancient Parts, 30× Ancient Core) automates the whole loop — assign two pals, pick a cake, and it breeds and hatches continuously with no separate incubator.