He wrote the setting for Diablo, Warcraft and Starcraft. He developed the story for Diablo 1 - 3 as well as most of the lore for the first 3 Warcraft games I believe.
There was no story for Diablo 1. At exile con the creators of Diablo talk about how there was no story and the execs at Blizzard tacked one on. Chris Metzen had nothing to do with it.
What? I played Diablo 1, it literally had a story? Chris Metzen co-created the setting for the franchise with David Brevik and Bill Roper in 1996. The changes Blizzard wanted made from the original concept of Diablo was to make it real-time rather than turn based and to add multiplayer as part of the publishing agreement. I don’t see anything about a storyline being “forced” on the developers.
https://youtu.be/0coFsOfLcPg?si=1JRdDva77SivwKN6
This is the interview. I don’t have a timestamp but the whole thing is compelling.
Basically David brevik said that there was no story and the cut scene on the end was added by blizzard south. They had no intent to add that.
I stand corrected though. Metzen is credited as a writer on Diablo. But not Diablo 2.
I suspect Metzen wrote the ending that was tacked on according to Brevik, since at that time blizzard north was a completely different team at the time.
