1. Download DeadCell.reg and run it.
(Right click and click "Save As")
2. Turn on Diablo 2 or Diablo 2 LOD
3. Look under the Battle.net button where it says Gateway and then has a US gateway and click it.
4. Click on the "rotts" gateway and then "ok"
5. Click on Battle.net and create an account. Note: it doesnt matter if you had one on blizzards server, this is a completely seperate server.
6. Create your char, and join the party! :D
To join Open Bnet fallow "How to Join Closed Bnet" to # 4.
5. Click on "Other Multiplayer" and click "Open Battle.net"
6. Create your account
7. Pick your character and join the party!
Whats the difference??
The difference is quite simple. Open Bnet is mainly used by hackers, those who like to duel their hacked characters and get really good at hacking Diablo characters, also you an use your single player characters on open bnet, where as in closed bnet you must be connected to the internet to play your character. However, closed bnet is almost impossible to hack unless you know exactly what you are doing and have access to my server (good luck with that).