First 5 signs that your friend plays too much Diablo 2:
5. He needs to buy a new mouse every week.

4. He oftens bables something about "The East".

3. He starts calling his locker his "stash".

2. He tells his parents he wants to go to Lut Gholein for their next vacation.

1. When you ask him to come with you to a place he's never been before, he asks you to send him a town portal when you get there.