Your mastery of defiling with simple spells allows you to cast them with alarming quickness.

Encounter   ✦     Arcane, Necrotic
Standard Action      Personal

Effect: You can use one of your at-will arcane attack powers as a free action. If the attack hits, the power deals 1d10 extra necrotic damage to one target hit by the attack. In addition, the next time you use an arcane attack power before the end of your next turn, you roll two dice for one attack roll and use either result.

Published in Dark Sun Campaign Setting, page(s) 64.