Faith
As with stamina in the physical arena, all inhabitants of the world also have a pool of Faith, allowing them to combat and overcome forces unseen, bolster their will and for some even manipulate creation itself. For player characters, the Faith pool comes from combining the core attributes of Intelligence and Virtue, the former being a measure of their learning potential and worldly knowledge with the latter being a sum of their overall will.
Every character will have a pool of faith, though few will use it in a more active way than a Constructor. Those who are not Constructors may still find it necessary to draw upon their Faith from time to time, to escape crippling unseen forces or to overcome powerful attacks upon their will.
Like Stamina, Faith is replenished through rest and characters will recuperate Faith at the same rate.