Overcharge

Overcharge is a passive talent.

In-game
The chance to create Crackling Energy seems to be independent from the spell's type and cost, potentially allowing some spells to generate more Mana than their own cost.

Ball Lightning, if used in Enchantment slot, will make this talent generate additional Ball Lightnings from other spells instead.

Development
Originally, Overcharge would make Lightning spells' Critical Strikes have up to a 1% chance per point to release 3. It triggered off Critical Hits of any Lightning spells and attacks, and the chance scaled with Proc Coefficient. Each Critical Hit and each enemy rolled their own chances check. were affected by all related enhancements and were cast at the current spell rank (rank 1 if not learned). This effect could chain repeatedly off its own Charged Bolts.