A completed orbit earns the Core one prize roll, and the odds scale strictly with the
height you burned: spend = 0.5 m × donors × days. A single roll can pay
out more than one of the four, so these are four independent chances, not one weighted pick.
Not rarity, not tier, not biome, not how many companions a piece already has. Pour budget comes from an age curve every piece shares, so a Legendary and a plain piece born the same day have exactly the same height to give.
Entry checks each donor has the full pour available up front. A never-poured piece holds 7.681 m right now, and 0.5 m a day runs that out at 15 days.
The ceiling rises with the collection. Thirty-day orbits need 15 m in hand, which arrives at collection day 21.
Scaling is linear and no orbit the contract allows can reach a cap, so one long orbit and several short ones that burn the same height carry the same odds. Twenty times the height is twenty times the chances, every time.
Companions and growths are progression and carry almost all the probability. Crown and Skull are status, and they are the only two outcomes the guaranteed milestone ladder can never hand out.