Well, some weapons do simply kill instantly. You can't avoid that. A marine should not survive a solid hit from a lascannon, melta gun, plasma cannon, etc. There are a few ways of increasing survivability, so that people don't just sit and snipe with high powered weapons, but that is more ways of the person avoiding taking the damage, rather than just taking multiple shots to go down.

Well, if we go by the lore, Space Marines should be able to shrug off most of what Ork and Eldar infantry weaponry can dish out, while the Marine with his basic weaponry, like the Bolter, should be heavily wounding/killing everything with a few shots. An equal number of Orks and Eldar would need to be bringing in some pretty heavy firepower in order to have any kind of chance against an equal number of Marines armed with their most basic weapons, and even then the odds would not be in the Orks/Eldar's favor.
That's obviously not going to work for the game.

I think durability should go by how it works in the TT. If a units armour can't handle a shot from a certain weapon in the TT, it shouldn't be able to in this game either.

Hopefully this game has forms of active mitigation via player skills or from support classes like apoth.

This game is going to have 24 classes(?) at launch. That's A LOT of diversity. TTK should be completely different based on the Class vs Class match ups. Thats well... what makes playing these types of games fun, the fact that each class plays differently, and group composition can play a huge role in how battles are fought/won.

TTK was my biggest complaint about Space Marine (the video game). Too easy to 1- or 2-shot people. That shouldn't be possible. I'd like it if SM/CSM were far more durable. It would be more realistic. That said, certain weapons should be 1-hitter quitters - i.e. Thunder Hammers, Meltaguns and charged-shot Plasma Cannons.

Note: With respect to Meltaguns, here's to hoping that they get it right - it's not a cone shot.

Yeah I think Space Marine has it about right. There are enough one-shot-kill weapons to mix it up and those that are have some limitation so they don't dominate - admittedly skilled players can still own.
Melta - OSK Up close/V short range.
Lascannon - OSK As a headshot only.
Plasma Cannon - OSK Takes time to charge then slow firing so it can be evaded.
Bolt Pistol - OSK As a headshot (when they have no armour)
Thunder Hammer - OSK combined with perk but slowest melee option.
Modified Grenade - OSK But only one issued unless combining with your final perk slot.

The classes helped to balance TTK too. Fastest moving troops (Assault) have lowest armour value. Slowest (Devastators) the Highest. Not by much but enough to make the difference and aid balance. If EC goes down the same route then I'll be happy.

I'll respond with more shortly, but you can't have one-shot weaponry in an FPS that is MMO-scaled, because it'll be abused till its removed outright, which wouldn't slant in that direction to begin with. As great as Space Marine was, it is not an experience that can be fully transmuted into this MMO experiment. You can't have one-hit-quitters, any MMO played doesn't stray from this, consequently, CoD would be the worst MMO if it took its original formula unfettered and applied to an MMO scale.

I'm stating this on the case-by-case game equivalents of heavy armor, but even some games didn't manage one-hitters going lighter in terms of armor. Plus, on such an epic scale, it will be hard to discover players in a large firefight undamaged that powerful infantry weaponry when precised can't shred wounded players around a battlefield.

I read that the Orks may be F2P, that's great, but I hope not in the sense that they have significantly weaker avatar stats than the powered armor forces. For an online game that wants to maintain balance regardless of the lore inside this MMO, will have all four races on the same footing, from class-to-class, or armor-to-armor however it works. An Ork player that will always be disadvantaged by Space Marines in survivability will not cut, and thus an Ork, Eldar and Space Marine must have the same health templates if this is an actual MMO. Yet again as I stressed before, an infantry weapon should only become one-shot if it actually has the maximum damage it can inflict upon an opposing player that isn't wearing the heaviest equipment. With a class-based system my evaluation still stands correctly I feel, for even the "lightest" classes of the four empires succumbing due to one-shots will be game-breaking.

Instead of the idea of one-shotters, if we had instead was movement to an area of two-four shots required to kill such and such it would be appropriate for this genre. Now, if EC's strongest sniper rifles on the highest-tier of their own hit a class with the weakest armor attribute, and it one-shot it, it would instantly become an area of tension amongst the community, but if the weapon took say, 80-90% of the player's health than its feasible, and playable. To suggest one-hitters is instantly moving the TTK rate to that of CoD's too.

@Naga

We still don't really know were the game will fall in between the TPS and RPG genre. The devs seem weary as to what to officially call the game, if you look at the main site its called a "3rd-person, Massive Combat RPG". I'm personally hoping for a 33% TPS and 66% RPG split.

In most FPS the only way to 1 shot someone is with a headshot from a sniper rifle or direct hit from anti vehicle weapons / vehicles themselves. Hopefully skills in EC are a bit more varied than "Shoot this" and "Shoot that". I'd really hate to see EC end up focusing too much on twitch based shooting. 40k fans up to this point aside from dirty casuals who only played Space Marine have all been players of RTS / MMO type games, and of course tabletop... which reward strategic thinking on the fly, and preparation. Theres nothing strategic or even "thinking" about getting killed before you can react to it.

Getting one shot by things like taking a direct hit from a baneblade or a plasma cannon as boy is one thing, but I'd really like to see some awesome combat between maybe 2 end game geared / skilled marines were each of us is using every ability we have and using every bit of mileage our builds are giving us desperately to come to a peak after maybe 8-12 seconds of intense fighting ending with one of us getting an execution sequence. Just somthing different than "Haha I shot you 1st noob!".

I hear what you're saying Naga and agree with it to be honest. The Lascannon (sniper weapon) in Space Marine was a TSK weapon and only became a OSK to the head - which takes some skill on a moving target. This ties in with what you'd like to see and the route I'd like the devs to incorporate too.

I think the RPG element of EC relates to the character progression, unlockables, relics to found etc and the MMO to the planned size, scale & grandeur of the levels, battles & players online the devs are hoping to have.

I personally hope for more of 66%TPS and 33%RPG - just going on how much I enjoy Space Marine.

You can't really translate fluff to gameplay very well here, if you did Eldar would just straight up die if they were hit by a bolt shell and OSK for one faction just completely breaks it.

The time to kill should be equal across the board, balance is much more important than sticking to the lore here. That's not to say that Orks should have a faster time to kill in melee than the Eldar would and vice versa for the ranged combat (as the Eldar are much better than orks in that respect).