Subtlety

Subtlety rogues are the masters of the shadows, and they strike unseen. They don’t have the lethal poison-tipped daggers of the assassin or the brawling prowess of the outlaw, but their acumen on the battlefield and ability to hide in plain sight are unrivaled. Some claim the art of subtlety looks like malevolent shadow magic—but no matter from where their power is derived, these rogues are capable of performing devastating assaults on their enemies, slipping away unharmed to strike again without detection. Most rogues train their entire lives to learn how to walk in the shadows—subtlety rogues were born there.

 

An extremely useful tool for overall optimization

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WoWhead Subtlety guide

http://www.wowhead.com/subtlety-rogue-guide

Icy Veins Subtelty guide

https://www.icy-veins.com/wow/subtlety-rogue-pve-dps-guide

Noxxic Subtlety guide

http://www.noxxic.com/wow/pve/rogue/subtlety/

Ravenholdt guide

http://www.ravenholdt.net/subtlety-guide/