Diablo Legend
The Diablo Legend refers to the in-world belief that the events taking place 20 years ago (in Diablo I and Diablo II) didn't really happen, or it only happened to a fraction of the magnitude that was claimed.
Contents
Background
Since most people who were involved were killed, and the few who were not went mad, not many eye witnesses of any credibility are left alive to tell the tales. Scholars and regular people all believe SOMETHING happened, but it could just as well have been weird mould growing in the wells of the few specific places that were affected, or some other "natural" reason.
People feel that if the Prime Evils were on Sanctuary, people would have noticed it!
Something Happened
People know something happened, and they recognize it was a great tragedy, but exactly what it was is not as certain, and people claiming it was Diablo as not generally believed, even if it's likely there are informed people out there, who do know.
