Coincidental Events

Wild magic fills the air around you at all times because of a curse. You've learned to control the wild magic's behavior, stopping dangerous spells from happening randomly and being able to use them, although it is not you casting them. Because of this curse, you are vulnerable to magic attacks and you constitution score decreases by 2 points.

Once per long/short rest, before you roll a d20 for an attempt at a spell of level 3 or lower, you can increase the roll of it by 3.

If what you got on the d20+3 is 13 or lower, what you are trying to do will backfire and happen to you if it's bad, or to the target if it's good. If you get above 13, your spell roll will happen via wild magic in the air around you, meaning you will not be responsible for it.