Riposte is a 10-Energy attack based on weapon damage. To use this ability, you must have recently parried an attack. This ability can be used on an enemy that wasn't even parried by you.
Limitations[]
Requires you to have recently parried an enemy's attack, which means that the enemy must be hitting you.
Tips and tactics[]
Riposte is most useful against warriors, hunters, paladins, and other rogues; slowing their weapons takes most of their bite away.
You cannot create macros that automatically check for buffs or debuffs on a target and change abilities accordingly, but you can create a macro that will randomly choose between your main attack and Riposte, like so:
/startattack
/castrandom Sinister Strike, Riposte
Useful in solo leveling, since it's pretty cheap (10 Energy) and lets you take advantage of the +6% parry chances.
The Floating Combat Text interface options can be set to display a message when Riposte becomes usable.