From Archon Arcana - The KeyForge Wiki
Each player has an Æmber pool, which is any convenient part of a player‘s play area that is distinct from the common supply.
Whenever a player “gains” Æmber, it is added to that player‘s Æmber pool. Whenever a player “loses” or “spends” Æmber, it is removed from their Æmber pool and returned to the common supply.
If you steal Æmber from your opponent, you move it from their Æmber pool to your own.
Related Topics: Æmber, Capture, Steal
—KeyForge Master Rulebook v17 April 2023