Rogues opt for a more "sophisticated" style of combat. They prefer to use tactical cunning coupled with stealth in order to win.
 Combat tactics
The key to playing a rogue (assuming you don't go the archer or straight bard route) is backstabbing: make sure to get behind opponents as often as possible, using Warrior skills Taunt and Threaten when necessary to distract them. This will ensure much more damage per hit, plus additional damage and effects when combined with Assassin talents.