Psyche is a run-exclusive resource — it is collected during a run and does not carry over between attempts. It is found in Soul rooms, as boss drop rewards, and occasionally purchased at Charon's shop. Some Arcana Cards grant bonus starting Psyche at the beginning of each run. Selene and Aphrodite boons can also provide Psyche-related bonuses mid-run to supplement income.

• Activating Arcana Card slots on the board during a run (each active card costs Psyche to maintain)
• Purchasing high-value boon replacements or items from Charon when Psyche is in surplus
• Determining the effective "build capacity" for the current run — more Psyche means more active Arcana

Psyche is the single most impactful in-run resource because it directly controls how many Arcana Cards can be active simultaneously. A run with abundant Psyche can maintain a fully loaded board; one with scarce Psyche must make difficult cuts. Always prioritise Soul rooms when routing, and plan which Arcana to keep active based on the current Psyche ceiling rather than which cards you own.