What Nihm says. For instance, the other day my wife and I were running our Wizards through a GR, pretty low level like 25 or so, but we have been away from the game for a while. This particular Wizard of mine is a full-on Firebird variant, burning stuff all over but a bit lacking on the durability side. In the middle of a massive scrum with two packs of champs or elites or Belial knows what (so many colors!), my Firebird passive proc’d. That is, I died, technically, and was revived by the meteor. Talk about a “change my cabalistic robes” moment.
It becomes a really interesting challenge, though, to balance gear, cube abilities, and skills to maximize offense–which is what makes the D3 world go round, no mistake about it–and survivability, which if you go too conservative will limit you to perpetually running low reward difficulty levels because you simply cannot kill stuff fast enough. This game is pretty much all TTK. When I first started, when the game came out, I invested heavily into health, regen, and defensive passives. I’d easily top 10 or 12 million durability but only 200 or 300k attack. No fun, because I could not kill much, and really, not very safe, either, because the longer you let stuff live the worse off you are. Period. Killing fast is by far the best defense. Once I realized you had balance it better, it got a lot more fun.
I still struggle to get the balance right; T6 is all I’ve been willing or able to go on any of my characters. I think I can do more, but the limitation is as always killing fast enough. Trying to understand the rather complex interrelationship between gear stats, gear abilities, your own skills, Paragon levels, and how you put them all together with stuff you cube, is challenging, in a good way. My guild, Amazon Basin’s Hardcore branch, has folks in it doing some amazing GR60 runs, but they have three times my Paragon levels as well (I’m at somewhere in the mid-200s).
Hardcore progression is otherwise pretty much the same I gather as soft core, except that you are much less likely to just wing it and see what happens. Once you have leveling stuff down, especially if you have people to leech off of and gems of ease, you don’t sweat losing the character so much as gear/gems. IF this was a game where you actually developed any attachment to specific characters, it would suck, but let’s be realistic. Your character’s name doesn’t even show up to anyone unless they inspect you. Your skills are totally malleable. Even gear for many builds is pretty easy to get, with enough time investment. So it’s mostly time you are risking, not emotional attachment.
This is so unlike Diablo II, where man, losing a character sucked balls.