Improved Arcane Explosion was a mage talent that decreased the casting time of the [Arcane Explosion] spell by 0.3 seconds per rank, up to 1.5 seconds at max rank. With a base cast time of 1.5 seconds, Arcane Explosion became instant cast with 5 points in this talent. With Patch 1.11, Arcane Explosion was changed to be instant-cast without talents. Improved Arcane Explosion was removed, and [Arcane Impact] took its place in the arcane tree.