A very common question I get as a rogue, and author of a Rogue Leveling Guide is what spec is best to level my rogue? Most people think they should use assassination or subtlety to level, since there are some very spiffy and neat abilities you get in these two talent trees. But on the contrary, combat is the most efficient and fastest leveling spec that you can use on your rogue when working your way up to level 80. This is because there is very little downtime with combat, which means you won’t have to stop and eat constantly and wait for your energy to regenerate.