Which NPC in WoW are safe to pass nearby?
Playing for Horde I was accidentally killed many time by Alliance NPC, when I happen to come near Alliance city. Usually it is immediate death, so I started to be afraid of NPC, which have "red" name and has a skull instead of level.
But then during quests I noted NPCs, which are also red and skulled, but they didn't touched me. Last one I met right in a neutral city – Dalaran, it was near a guy, which gave me a quest, so I must come close to this skull.. and it didn't touched me.
So is there a reliable way to understand when NPC will kill you and when they will ignore you?
P.S. I add a sample picture of red mob, which doesn't attack from a beach of Isle of Giants (NPC named Beeble Sockwrench) (this is not city area):
Best Answer
The first thing to look for is if you could attack the NPC (move your mouse cursor over them, if it's a sword you can attack them, if it's a hand you can do nothing to/with that npc, if it's another cursor you can interact with them in a friendly way). If you can't attack the NPC, the NPC won't attack you.
If you can attack the NPC, the NPC can attack you (back). But not all NPCs are aggressive and will you attack on sight. Some will (with variable distance at which they attack, this is called "aggro range"), some won't. Regretfully there is no way to check if the NPC will attack you on sight or only fight back when attacked.
For most situations you learn by experience what to expect from an NPC. And with higher level your chance to escape if attacked also improves so it's no longer deadly when you aggro an NPC.