Altar Dust

Altar Dust is a currency used to buy perks in the Fallen Altar incursion perk tree. It is tied to Incursions and is primarily obtained from Gateway Tablet rewards, making those rewards the main way to build up a supply for perk progression.

It can also be dropped by Monsters if the tier 1 perk More Dust! is taken, and by Caveling if the tier 2 perk Caveling Invasion is unlocked. These perk interactions make Altar Dust part of the incursion reward loop, since the amount you gain can be increased through the perk tree itself.

As of version 1.0.1, it takes 20,780 Altar Dust to max out an incursion perk tree. This gives a useful benchmark for how much currency is needed if the goal is to fully complete the Fallen Altar perk progression.