WoW TBC Classic - Shadow Labyrinth Easy Farming/Grinding Method (Ranged) (Patreon)

When you enter the Shadow Labyrinth instance there is a ledge on the wall to the right of you which leads to a brazier burning with green fire.

If you jump on this ledge having attacked a mob it will go to the right of the room, get on the ledge, and then follow the ledge around to your location. It is weird, slow pathing, and with a little practice you can keep any melee mob or mobs effectively pacified while you kill them with ranged attacks.

Pathing exploitation is a well known way to exploit instances but this one is unusually accessible being right next to the instance entrance. 

Because there are multiple caster mobs in the instance you can't pull the whole dungeon using this trick, but it is possible to pull multiple groups mobs at a time and gain very good experience and/or an opportunity to farm fel armanents plus other tbc drops. *

There is much less chance of dying using this strategy than with most similar pathing glitches since the exit portal provides a handy escape route if something goes wrong, you can also jump on the ledge on the left-hand side and reset everything. 

*On youtube there is a strong focus on pulling multiple mobs and gaining very high experience gain per hour in several popular videos, usually but not exclusively associated with frost mage strategies. It is worth mentioning however that even if you can simply kill one elite mob per minute will give much better experience in the 67+ bracket than questing or grinding normal mobs.