The map rolls a biome every second, on that biome's own chance. A chat line announces the spawn, except Normal and GLITCHED. Time of day is a second system: about 2 minutes 30 seconds of day and the same of night.
What breakthrough actually does
An aura's native rarity applies in its own biome. Outside that biome, the listed rarity is worse. The biome's breakthrough multiplier is the gap between those two figures. Abyssal Hunter is the worked example: 1 in 100,000,000 in RAINY, and 1 in 400,000,000 otherwise, matching RAINY's 4x multiplier.
The multiplier does not add to your luck. Potions, gear, and the grail are separate. Some auras have no breakthrough path and only exist in the native biome. Empty is one of those for NULL. The aura named BREAKTHROUGH, at 1 in 1,999,999,999, cannot be rolled during NULL even though NULL's multiplier is 1000x.
GLITCHED has no multiplier of its own. While it is up, auras native to non-rare biomes use their native rarity. DREAMSPACE also has no breakthrough multiplier.
When to wait
| Situation | Choice |
|---|---|
| The biome is common, such as WINDY at 1 in 500 per second | Wait and roll native |
| The window is long enough for your potion | Pop speed or lucky potions inside the native biome |
| The biome is GLITCHED, DREAMSPACE, CYBERSPACE, or THE RADIANT FOREST | Do not wait on the normal per-second table alone |
| You only have a one-roll Heavenly or Oblivion | Spend it in the native biome, or accept the worse breakthrough figure |
CYBERSPACE is 1 in 5,000 on a Strange Controller or Biome Randomizer, lasting 12 minutes. SINGULARITY replaces STARFALL at 1 in 100, or opens from a Singularity Catalyst, and lasts 20 minutes or until ASTRAIOS. THE RADIANT FOREST is only Condensed Memory inside LOST FOREST at night. Details are on the Radiant Forest page.
The biome infographic used on this page is MattPlays607's version 2.00 chart.
Standard spawn and duration figures are on each biome entry under Biomes.