Unstable Magic

Your surges of untamed magic are like a ticking bomb. Each time you cast a sorcerer spell of 1st level or higher, roll a d20. The DC for this effect increases by or for each time you do not surge, and reset after a surge occurs. 

As the DC increases, the static charge of your magic begins to manifest around you, and the power of your sorcery makes itself known. At DC 5, sparks of heated energy may come off the sweat of your skin or you may experience static shock when you touch another creature. At DC 10, smoke may begin to smoulder off your body or large wreathes of illusory blue flames may envelop your head as you cast.