Gameplay
There are many features that are universal in the Diablo series. Point and click means that the mouse is mainly used for moving and using abilities. Diablo heavily relies on the need to get better items. Items are randomly generated and usually have many attributes assigned to them. Various maps in the Diablo world are randomly generated in each game, which increases the replayability.
Due to its randomly generated maps and "Hack and slash" nature, Diablo may be loosely considered a roguelike, though with realtime gameplay, graphics and sound. It was in fact originally conceived and pitched to Blizzard as what amounted to a graphical roguelike. The adventurer being based in a town above the dungeon and being able to use "scrolls of town portal" is a specific influence from Moria.
Read more about this topic: Diablo Novels