[dolni]

No, it wasn't always nebulous. Roguelike was a well-established genre for decades before it got hijacked and now means nothing.

Like all genres, games within the roguelike genre (or what some people call "traditional roguelikes") have some variance. But if you played two games in the "traditional roguelike" genre, you'd definitely feel the similarities.

These days if you pick two random games on Steam with the "roguelike" tag, you're going to get two experiences which are not even reminiscent of the other.