Regeneration occurs after initial care.
Every 24 hours, a character gets a regeneration roll, provided they do not strain themselves too much.
During natural regeneration, a D6 restores lost hit points.
A Medicus can additionally use the successes of a Medicine check per day to restore hit points.
An Alchemist can support natural regeneration with potions or salves.
There are also other paths that support natural regeneration. These are each listed in the Profession.