D4 Harcore PvP. Permadeath, yay, nay or both?

That should definitely exist. Offense vs. defense, single target vs. aoe, single dmg type vs. multi dmg types, direct dmg vs. dots, and so on.

And yeah, the drawback to playing a sturdy mage should primarily be lower dmg, or less ways to deal effective dmg (like having to be in melee instead of range). Which should also be the drawback to playing a sturdy barbarian. The drawbacks can also be other stuff, like lower mobility for example.

It is. In D3 the only way to progress is by playing glass cannon, due to the GRift timer.
That is changing a bit on GRift 150 of course, due to clear speeds having gone below 15 minutes, so you can potentially start trading offense for defense.
Still no way for a sturdy barbarian to spend 30 minutes clearing a GRift though.

Hopefully yeah, but you would no longer be cornered.

I think that’s a wrong answer. Your luck will run out when you dare. You can not hope to achieve something when you throw yourself on a large crowd of monsters in Hardcore mode then think you can bail out whenever you want. This doesn’t apply in Diablo 2, nor in Diablo 3; with improved intelligent loop of D3 monsters even less so in there.

Only a matter of time when you face fast chasers. Different monsters will have different characteristics and means of moving. When you fail to pin them, they won’t let you get away easily because you imagined so.

You also cant progress without the appropriate damage. So in the end, you will need basically the same dmg on HC as on SC. Going tanky is not a real choice in D3, unfortunately. But that is more a GRift design flaw than it is a build option flaw.

That’s not really detrimental to your defense ability and survival. At the end game, a Hardcore character will be more sturdy and pick the safest option instead of full blown damage compared to a Softcore character. You’ll care to possess more vitality on some pieces and pick safe house defensive ability triggers instead of damage buffs. You just have a longer farming and build up in Hardcore mode because the risk is high compared to Softcore.

I’d be cool with cheat deaths, but I can get on board with this no-absolutes concept as well. I think it’s not entirely about 100% effective defense, but about 100% effective 100% of the time. Things like vengeance and IP in D3 are a bit lame mostly because they can get 100% uptime. I think it’d be exciting with 100% immunities (to cc, to elemental damage, or even cheat death) that comes with non-trivial conditions. That wouldn’t be online all the time. Like, use some skill that gives you fire immunity (or even fire-healing like the amulets) for 3 seconds to tank the molten explosions, but on a CD that only starts after duration is over. Like smoke screen, but probably on a longer CD, depends how CDR heavy D4 will be I guess. Similar abilities for short time cc-immunity could work. It’d add skill to the game, and would allow people to play over their limit if they execute well.

Same for cheat death, press a button (on long cooldown), and you have a cheat death for a few seconds. The monk in heroes of the storm, Kharazim, has exactly that, an ultimate ability “Divine Palm” on a long CD that he casts on an ally, and if the person is killed within 3 (I think?) seconds, they go in stasis for a couple seconds and get a big heal when coming out. I think that is very exciting gameplay that could work as cheat death. I would love that ability on a support as well! Such a spectacular way of saving an ally from death, and imagine doing that in HC! The support would be the star of the show for once!

Diablo 4 doesnt need pvp. Im okay with it being strictly PvE.

Yes, stuff like Monks Serenity can be okay (well, the cooldown need to start after the duration ends, so you cant get anywhere near full uptime).
For those the issue is permanency, or an uptime high enough that it nearly has the same result. Like 50% uptime would still be way way too much, considering you have time between enemies too, so a 50% uptime could easily result in 100% uptime when it matters.
For immunity skills, uptime should be more like 5-10% at most. Something you use when it truly matters. Something you cant rely on all the time.

Cheat death is different. Partly because it is passive. You dont need to press a button that makes you unable to die for 1 second. It just sits there, waiting for when you need it. Which in a way gives it a 100% uptime - it just passively works when you need it. Only more so if you make sure to disengage from combat after it has triggered, waiting for the cooldown to come back. A complete lack of player input.

:+1:
Yeah, also a common skill in D&D style RPGs. And it can be very nice.

I dont think such a skill should be castable on others in Diablo since I dont think support builds should be a thing. But as a self-cast, sure.