A mundane effect , also known as an incantation is a rote or other magical effect that has become so believable that it works for the Unenlightened. Mundane effects are within consensual reality, and cannot incur Paradox.
While vulgar magic is the obvious overriding of the Consensus, and coincidental magic is the subversion of consensual belief, mundane effects are the heart of the Consensus.
The functioning of firearms, steam engines, and instant messaging are all magical effects once subject to Paradox that have become integrated into the consensus to such a degree that they are essentially taken for granted, and function without the force of will required to bend reality.
Vulgar and coincidental are subjective, and often depend on the perspective of the Consensus of the local area. A Verbena's health potion might be incredulous in a modern western city, but might go uncontested in a rural eastern European farming village, and could even be mundane in a Verbena Seasonal Realm.
Modern examples of non-scientific mundane effects include demon summoning, forbiddance and warding against wraiths, African healing rituals, protection charms and curses.