As part of the push to involve the designers more in production, I made a scripting engine and language to drive the quests in Diablo 2 roughly as you describe.

As part of the push to involve the designers more in production, I made a scripting engine and language to drive the quests in Diablo 2 roughly as you describe. By the time we go close to the end, none of the designers bothered to use it (we officially only had one at our studio but many people dabbled) so for my convenience I just took it out and replaced it with a function table that was there originally, I really regret that because I imagine the unofficial mod scene would be even more amazing if I left it in. The objects and monsters worked roughly as you describe, adding new ones (without new features) meant just adding and customizing a new line in the appropriate spreadsheets.