These are skills that aid the player character in adventuring when not in combat. These are also skills that allow the character to have some profession between campaigns. A Warrior, for instance, might be a blacksmith between adventures. A Wishsinger might also be a craftsman of musical instruments. A Priest might also be a teacher. Thus, the character’s non-combat skills allow her to pay the bills between adventurers.
All non-combat skill checks are determined by rolling a 20-sided die. A success is indicated by rolling the character's associated attribute (i.e. Endurance, Perception, etc.) or less on the die. The check is gains a +1 bonus for each intensity level past the first that a character has in a given skill. So, if a character has Intensity (3) Blacksmithing, he would gain +2 to his Blacksmithing checks.
GM Note: Keep an eye on character’s skill progression and, if needed, feel free to force characters to actually seek out people to teach them non-combat skills. This prevents characters from just “learning” a currently valuable non-combat skill when leveling up even when their character had no opportunity to learn that skill or previous use for it. For example, unschooled Barbarians that just “happen” to know Engineering (because Engineering has suddenly become useful in the campaign) reduce the credibility of the adventure and the adventuring world.