For me, roguelike = procedural generation + permadeath, that's all. Some people call these games "roguelites", and have a much stricter definition for "roguelike", but I still consider it one of the best defined genre.
Procedural generation and permadeath are a perfect combination. Permadeath is a powerful mechanic, but by itself, it is very frustrating, because if you die, it forces you start over and redo everything you have done. Procedural generation solves the problem by making every game unique. We probably can add a form of character building and progression to the definition, otherwise death would be meaningless and it would be more like a traditional arcade game.
There are other aspects to traditional roguelikes: turn-based, dungeon crawlers, resource management, hack-and-slash, etc... But none of these aspect synergize as well as procedural generation and permadeath, that's why I consider it the true defining feature.
Procedural generation and permadeath are a perfect combination. Permadeath is a powerful mechanic, but by itself, it is very frustrating, because if you die, it forces you start over and redo everything you have done. Procedural generation solves the problem by making every game unique. We probably can add a form of character building and progression to the definition, otherwise death would be meaningless and it would be more like a traditional arcade game.
There are other aspects to traditional roguelikes: turn-based, dungeon crawlers, resource management, hack-and-slash, etc... But none of these aspect synergize as well as procedural generation and permadeath, that's why I consider it the true defining feature.