Children of the Glyphs mechanics
(Background information for the Children of the Glyphs campaign)
If a PC attempts something significant, the relevant attribute is compared with either a difficulty number or, if the action is opposed, the opposing character's attribute. After taking into account any bonuses and penalties that may apply, the higher number succeeds. The greater the margin of success or, the better the result, and vice versa.
When actions are time-critical (such as in combat), the action moves into rounds, each of which has a mundane phase followed by a magical phase. A character may act in one or both phases, depending on what they're doing.
In addition to whatever special abilities they confer, Glyphs also boost a relevant attribute. The attribute bonus is a passive, "always-on" effect, but any other abilities must be activated. For some Glyphs, there may be a cost necessary to maintain it while active, while others simply remain "on" until deactivated, or until the relevant attunement dissolves.
To use a Glyph, it must be inscribed on the flesh. For Birthright and Custodial Glyphs, tattoos are usual, while Chaos Glyphs may simply be scratched into the skin at the time of creation.