Diablo by Blizzard is by many considered a commercial roguelike. The first reaction to such a comparision may provoke laughter, but when analyzed carefully we will see how many simmilarities there are.
Similarities to Roguelikes
- Diablo features a world that structuraly is identical to Angband or Moria: a town level where you can buy things and a multi-level dungeon below.
- The dungeons are randomly generated, so is the item and monster placing.
- The game is hack'n'slash focused.
- Inventory management is an issue (again similar to Angband).
- All the standard roguelike subset features of cRPG's apply (classes, character levels, stats, etc)
Differences to Roguelikes
- Diablo has graphics. This difference isn't so valid today - many traditional roguelikes have tilesets, many in-dev roguelikes have graphics. Also isometric perspective was also used in roguelikes. The only thing that differs Diablo here is the fact that it has animations and nice isometric-tiles (Iso-Angband). Yet, this is something that a unpaid hobby developer usualy can't do on his own.
- Diablo is realtime. This one also might be considered invalid. Some of the recently developed games that want to be called roguelikes have reltime (for example 3059 or Egoboo).
- Diablo has music and sounds. Well, here DoomRL is a counter-example of a roguelike game that successfuly implements sounds and music. Also some Angband and NetHack interfaces have sound.
The designers of Diablo admitted in an interview that they were inspired by NetHack. As wether Diablo is a part of the roguelike genre remains a question.
An interesting project was undertaken by Kornel Kisielewicz in this field. He took the original underlying mechanics of Diablo and implemented them into a roguelike framework as his 7DRL entry. He based on the pre-release demo of Blizzard, so the amnount of contents is heavily reduced. The result was a simple, yet playable coffeebreak roguelike called DiabloRL.