Yea it would be hard to stop in the middle of the fight and execute unless it was a small skirmish where two groups of guys happened upon each other. Now with that said maybe you get a short time buff for doing an execution but you run the risk of being open for attack during so, that will always give the player the option of going for the buff vs playing it safe, just another element of strategy.

I think they should be fluid with melee and have a disengage command. When you're in a melee fight you aren't focused on your surroundings you're focus on your opponent. At this point it's your team's job to cover you. It would make sense to be in the middle of an execution and a teammate calls on vox..."Break off" and you halt the execution and move to cover. It wouldn't make a lot of sense to have the 3rd person awareness to be able to make that call yourself. I see how people would get mad because they're in an execution and they get fragged.. I do see that.. but that's realistic. If you run into a room and end up instantly face to face with the enemy and in a brawl... you're not going to have the awareness to cover your flanks or the corners ect... Your team picks up the slack while you handle your business.

I think the executions should be technical in such a way that the player is "engaged" in making it happen.. nothing automatic.. so you get the actual sensation of that 1 on 1 melee focus.

Thanks for all the replays guys!
Seems i didn't cover all the angles, while we talked in my guild about executions, few people said that they didn't like it in GW2 cause it was destroying fluidity of fight, cause as soon as an enemy would get in "downed" state, everyone around you would drop what they were doing and jump at opportunity to finish someone off.

So i was thinking of a way to implement executions/finishers without breaking the fluidity of fight.
But after all your posts, i wonder are executions even viable for this game? Perhaps once you drop someone to 0 HP, they should be dead (unless a teammate resurects them) like in FPS games (Battlefield series or Call of duty), and then perhaps leave executions for some kind of Arena Mod for the game (that could be released one day).

Space Marine did a good job of keeping the combat fluid in the campaign. Something similar, where the enemy has to be stunned b chaining a stun into a combo/parrying an attack and then stunning for the execution to work, would work in theory without breaking the flow and, as you'd be close, it'd stop people swarming for an execution. Of course, there'd have to be the ability to fight back, like the Nobs and Chaos Marines did, so the tables can be turned.

Running out of HP from small arms fire (Bolters, Shootas etc) should results in a downed/bleed-out state without any ability for execution (short of emptying a clip into the target or throwing a grenade.)

The GW2 "I'm down, but still able to cause some mild mayhem", followed by "No, I'm dead and out of the game, but can be resurrected very quickly", followed by "Damn, he's done an execution on me. Back to the spawn point I go..." wasn't a bad model in principle.

In practice, in most small-scale skirmishes or outside the front line on larger ones, you'd regularly see 8-10 people all standing around attempting an execution in a race to do it. Not so good. The important thing is that the strategic advantage of conducting an execution to the team is balanced with the strategic disadvantage of losing (at least) one squad member to doing it for a few seconds. And this has to be looked at from a realm perspective - GW2 passed the reward to the individual, which makes sense, but was a mistake as it introduced and rewarded selfish tactics that actually went against what made sense for the overall realm.

If they do executions they have to be voluntary and shouldn't give any extra points/xp/whatever. Zmalamuth had a good point on everybody coming in to steal your kill if it's worth points. Auto executions would just get me killed and that would pi$$ me off and adding temp invulnerability would be unfair. What if I have a great shot lined up to save my squad mate and then the enemy goes into invulnerable mode? Super frustrating. I could maybe see ranged executions that are target only animation but that's it.
"For the Lion!"

Make them randomized.
For shooting - think "The Darkness" style executions
and for melee - have it be some auto head cleave and a fluid motion like it just meant to happen - I’ve seen examples of this in games like "soul reaver" it was nice to break up the hack and slash.

I hope the Executions are really fast because they certainly will not make us invulnerable while we execute them.
(invulnerability leads to the old problem of kill -> execution -> kill -> execution, leaving the executing char sometimes invulnerable for a very long time, especially in the thick of battle this could lead to long killstreaks with lots of ae going on)
So please make them FAST and not able to turnoff, or else everyone will turn them off.
Also adding a few bonus xp or whatever else would not hurt as we loose fighting time with each execution.

All who have played War of the Roses can attest to what i am going to say now: "NO FOR THE LOVE OF GOD NO!!!" What you will get is a stupid stand around a wounded player fest, just to get that killing blow in BS which ruins the whole immersion.