Source is an additional resource all Contractors automatically receive when they get their first Power. It can be used in place of Exertion to activate Powers.
When a Contractor gets their first Power, they receive a Source pool with a Capacity of 1. This Capacity can be increased by spending (current rating x 2) Experience Points. Spent Source regenerates at a rate of one point per day.
Each Contractor's Source pool may be renamed to match flavor of the source of their Powers (their paradigm). For example, a Pyromancer that fuels their Powers with their inner rage may have a Rage pool.