Diablo 3 Season
Update: Now we know!
Blizzard has a ton of titles in lots of genres to try out, so of course people who enjoy one of them won't necessarily enjoy all of them.
So you've been persuaded to try Diablo 3 (maybe you read about the basics). You've loaded into the game, and now you're faced with the question of what game mode to play. There are many modes of play in Diablo 3 and some of the modes refer to what content you're playing rather than what difficulty.
In World of Warcraft, "hardcore" is a term often found opposite "casual" in those heated debates about whether time spent should be equal to rewards received. But in Diablo 3, "hardcore" isn't a player-generated term to describe other players -- Hardcore is a specific game mode.