Kick

Kick is a rogue ability that interrupts spellcasting. If Kick interrupts a spell, it also prevents the target from casting any spells from that spell's school for 5 seconds. Kick costs 25 energy.

Talent improvement
Improved Kick gives your a Kick an additional 50% or 100% chance to silence your target for 2 seconds.

Tips and tactics
Properly staggering the cooldowns of Kick, Kidney Shot, and Gouge can keep a caster almost completely crippled for the duration of a battle.