Battle Dot Net

Originally, Blizzard authenticators were small handheld devices that showed you a code that allowed you to log into Battle.net — but times have changed, and the physical authenticator we once knew is now a convenient phone app.

Battle.net has been a part of Blizzard's gaming presence since the days of Diablo 2, and over the years it's been integrated so thoroughly into Blizzard's games that other companies have basically tried to rip it off, with mixed success.