How Diablo Saved the Computer RPG

1UP's Thierry Nguyen penned an editorial with an arguably very controversial thesis, namely that the original Diablo reinvigorated a dying RPG market. I'm not sure if the article does enough to support it, but at least it works as a decent retrospective for Blizzard's seminal title. Here's a sampling:
But what was it about Diablo that had reinvigorated the dying RPG market? Co-founder Erich Schaefer's post-mortem on Diablo II touches upon the below central tenets of Diablo that Blizzard North maintained for Diablo II; these provide a pretty good shorthand for Diablo's success:

'¢ Make sure everything reinforces, and remains in service, to the basic gameplay of: "kill/reward."
'¢ Feature randomly generated content.
'¢ Pass the "Mom test" in terms of ease of play.
'¢ Expand on the Battle.net service that launched with Diablo.

Diablo's most contentious feature that governed the first and third points above-- its shift to a realtime combat system -- would ultimately end up being the very thing that both separated it from the rest of the genre, and helped define an entire sub-genre. As mentioned before, previous RPGs were turn-based affairs full of number crunching. Whether you're playing a classic first-person game like Might & Magic: The World of Xeen or a top-down RPG like Dark Sun: Shattered Lands, or even the new-at-the-time Daggerfall, you were governed by strict rulesets involving die rolls, initiative values, and turns. Even though the Ultima Underworld spin-offs were also real-time, there was enough studious thinking, exploration, and small pockets of enemies for those games to feel closer to RPG than action. By contrast, Diablo required constant and rapid mouse clicking -- button presses in Diablo rivaled those of shooters like Doom. It's often derided as an action game masquerading as an RPG.

Even as such, the mouse-click-heavy gameplay provided a low barrier of entry that simply allowed more people to play it. It might have required a bit more dexterity than a typical RPG, but it was certainly a lot less intimidating than figuring out the math behind THAC0 versus Armor Class. In keeping with Schaefer's mentioned "Mom test," you can put anyone in front of Diablo and say, "click over there to go there. Click on that thing to kill it. Click on that thing on the ground to pick it up. Click on that other thing to use it." While numerous spells, abilities, character progression, and other traditional RPG mechanics were layered onto the gameplay, it still can ultimately be reduced to, "click on this to make something happen."