PASSIVE SKILL INHERITANCE
What are your real odds of breeding that passive combo?
Pick what each parent already has. Every other Palworld breeding guide gives you a rule of thumb — this runs the game's own weighted-roll formula and tells you the exact probability, the expected number of eggs, and roughly how long that will take.
4 UNIQUE PASSIVES BETWEEN THEM · CLICK TO EXCLUDE ONE
| Total passives | Your 4 desired | Extra random | Chance |
|---|---|---|---|
| 4 | all 4 | none | 10.00% |
How the odds are calculated
Palworld rolls twice, independently, every time an egg is produced. First it combines both parents' passives into one list with duplicates removed, then rolls how many of those to inherit — 1 passive 40% of the time, 2 at 30%, 3 at 20%, 4 at 10% — and picks that many at random from the combined list. Second, it rolls how many extra random passives to add on top of that: 0 extra 40% of the time, 1 at 30%, 2 at 20%, 3 at 10%, capped at the 4-slot total.
Those two weighted-roll tables come from Combi_PassiveInheritNum: [4,3,2,1] and Combi_PassiveRandomAddNum: [4,3,2,1]in the game's own BP_PalGameSetting data, first disassembled by Reddit user u/mgxts and implemented in the open-source breeding solver PalCalc. We independently re-derived the probability formula from that mechanic and checked it three ways: it reproduces palworld.wiki.gg's own published table (40% / 24% / 12% / 10% for inheriting an entire 1/2/3/4-passive pool with no extras), it matches PalCalc's worked examples exactly, and it matches a million-trial simulation of the raw mechanic. Notably, the wiki's own prose descriptionof the mechanic — comparing two rolls on the same 1-4 scale — does not reproduce the wiki's own numbers; only the two-independent-rolls version above does.
This calculator answers "what is the chance of ending up with exactly my chosen passives," and, separately, "what is the chance of getting at least those passives, extras allowed." It does not try to predict which specific extra passive would show up in a random slot — that is a different, much looser question.
Passive breeding FAQ
How does passive skill inheritance actually work in Palworld?
Two independent rolls. First, the game combines both parents' passives into one deduplicated list and rolls how many to inherit (1 with 40% odds, 2 with 30%, 3 with 20%, 4 with 10%), then picks that many at random from the list — capped at the list's size if it's smaller. Second, an independent roll decides how many extra random passives to add on top (0 with 40% odds, 1 with 30%, 2 with 20%, 3 with 10%), up to the 4-slot cap.
Why do some calculators give different numbers for the same passives?
The most common mistake is assuming the second roll uses the same 1-4 scale as the first. It doesn't: the random-addition roll is 0-3, not 1-4, and it runs independently rather than being compared against the first roll. Get that wrong and every probability past the simplest case comes out wrong.
Does it matter which specific extra passive shows up?
Not for this calculator. It answers 'what are the odds I get my exact target set, with or without extras' — the count of extras, not their identity. Predicting which specific passive fills an extra slot would need the full random-inheritance weight table for all 115 passives, which is a separate, looser question from hitting your target set.
Does having a passive on both parents make it more likely to inherit?
No. The game deduplicates the combined list before rolling, so a passive present on both parents counts once, same odds as if only one parent had it. A 2+2 split, a 3+1 split, and a 4+0 split with the same total unique passives all behave identically.
What about Special Cakes?
A Special Cake forces the inheritance roll to 4 (PassiveInheritCountOverride=4 in the game data), guaranteeing the child inherits every one of the combined parent passives, up to 4. It has no effect on the separate random-addition roll. This calculator estimates the normal-cake case; treat Special Cakes as a way to force the 'roll = 4' row in the breakdown table.