I recently changed zone and suddenly most enemies are impossible to grab, every time I try, even if they didn't noticed me at all, they immediately get free and start shooting.

What determine if a grab will be successful or not ? Is there an attribute or skill to increase the chances or is it simply that enemies with a higher level / thread level are "in-grabable" ?

It should be determined by the body stat, but there is also a skill that enemies can have that doesnt let you grab them.
If you got a hacking implant, check for that on the skills they got.

Yeah, you need to get stronger (Body skills).

Do they have a skull over their head? Then they're too strong for you and will get free. It's explained in the tutorial.

That's what I suspected, thanks for the info.

I just found that a little silly, if you create a "stealth" build then you are not supposed to pour tons of points into your "body" stats, but you are kind of forced too otherwise you can no longer silently take down enemies.

Takedowns keep working, when there are big level differences (skull symbol) you will always fail.
Certain enemies got skills to counter takedowns, same for some enemies with anti hacking skills.

Its just to give you an extra hard time. If you still want to take them down silently, you can use non lethal weapons.
1.You can get a chip mod that turns all of your damage to non lethal
2.You can mod a weapon to become non lethal.
3.You can use non lethal melee.

If you still want to remain hidden, i would recommend a non lethal pistol mod combined with non lethal hacks.

Yup, I'm used to getting athletic or techie stuff from other games, if I want to play stealth, not Rambo points.

Btw. stealth-playing with body-stats:You also need them to force some doors open to get an extra route around patrolling enemies or to get into security rooms for deactivation of security systems.

Ummm you dont need body for that, you get the upper right one? Technical abilities, that will help you open pretty much everything that is not hackeable.

That also helps you craft better weapons/armors if you decide.

So a mix for stealth, that works would be either:
-intelligence+technical abilities.
-reflexes+intelligence (albeit you wont be able to force doors open)
-reflexes+technical (you can still hack doors open)

Now if you want to go silent assassin:
-reflexes+cool (some places got keycards you can get from neutralizing enemies)

Reflexes can give you either sniper rifle skills/knife/sword/pistol skills that can be mixed with silent skills from cool, like throwing knives.

Not every door though - some of them only open with body stats, no techie, no hacking. Happened to me twice yesterday. One of them didn't matter that much, because the enemies could easily be taken down silently and the other one, well, I got around by sneaking very akwardly (as I'm not sure you're supposed to climb/glitch up there the way I did it).

Which mission? I havent had any issue with the build im doing right now and i only got the basic body stats.
I can move around everywhere pretty much, and the doors i didnt had enough tech to open i just sneaked around for another entrance.

And even if you dont got enough body, cant you just put on an arm implant (gorilla arms i think) to force doors open instead?

Gorilla Arms: Maybe - i'm not that far that I can get them. I don't have enough streetcred.

Door nr.2 was in one of the main quests [POTENTIAL SPOILERS]:In the factory, where you have to save Evelyn Parker, when you take the route through the backdoor. There is a door I suspect to either give another way around the enemies or giving better view for distraction-hacking. But I didn't get in.

Door nr.1 wasn't tied to a quest I believe, just me jerking around...

But given that the game just released, I can't claim that I'm sure this was intentional and not just a bit buggy.


Edit: How come this forum doesn't have Spoiler tags?

Grabbing isn't necessary for a stealth takedown. Melee or silenced ranged weapons won't break your stealth assuming you kill the target with one hit and you dispose of the body before it's found (quick hacks will also work, though unless you can kill in the one hack you need to use something that prevents the target raising the alarm before they die).

The monowire is tailor made for assassination if you've went with a stealth build, assuming you're putting points into Cool.