The Making of Diablo

EDGE is offering a making of/retrospective article on the original Diablo, with excerpts coming from ex-Blizzard devs such as Max Schaefer and David Breivik. And while I suppose for a lot of Diablo connoisseurs the info won't be new, I admit I didn't expect to read that X-COM: UFO Defense was an influence, of all games:
(For me, the most direct influence was X-COM: UFO Defense,) suggests Erich. (The size of the characters, the camera angle and the tile-based random maps. I felt like it would make a great dungeon crawl.) Blizzard agreed, and Condor soon had a contract.

The game's central concept loot and monsters without the waiting was never in question, but that doesn't mean it emerged fully formed. Surprisingly, the ultimate action-RPG was originally turn-based. (At first we had it so that you would take a step and then the monsters would,) says Erich. (You would swing your sword and then the monsters got their chance. I think this was based on the Nethack or Rogue-style of game that Brevik liked a lot.)

Blizzard suggested switching to realtime combat, and a huge piece of Diablo fell into place. (The moment I put the change in, clicked on a skeleton and my character walked over and smacked it to pieces, the clouds parted,) says Brevik, who locked himself in his office for a week to rewrite the necessary code. (The magic was found.)

With the game starting to take shape, there were still plenty of hurdles to overcome. Like X-COM, Diablo would use randomised content, handing over certain elements of the dungeon designs to the CPU itself: the coding equivalent of Russian roulette. The system had to be able to create maps that weren't mangled, impersonal disasters. (This was the big differentiator between what was traditional and what was different to Diablo,) says Brevik. (Randomisation was very hard to implement because we didn't have any tools to do this. The secret was iteration. We just played and tweaked the content over and over again.)