How to kill a robot？ 9mm ammo can't do DMG to it.

[Mr.Hoooose]

And anyone who know how to use a grenade? I skipped the tutorial.

[[TwitchTV] TorNis]

Robots have cut damage weakness. Basically Shotguns or Melee weapons.
Or just use anything that does more than 20+ damage per bullet/shot.

Grenades can be used by putting item into quick use slot in middle bottom part of the UI

[FxFighter]

Originally posted by a1196673378:

And anyone who know how to use a grenade? I skipped the tutorial.

The early ones seem to only have 1 movement so you can also just not fight them and run around instead.

[Neyreyan_Youtube]

Originally posted by a1196673378:

And anyone who know how to use a grenade? I skipped the tutorial.

heavy ammo is the best way to do it, a chainsword or vibroblade works as well, shotguns are the third option.
The quasi guns also do the job
basically anything but small caliber ammo

[Trevor Drakenor]

I had to bring a melee cutting weapon to fight those, you can also spray at them and hope one of the bullet take off its head, or destroy enough of its part and let it bleed out. Grenade and barrel does nothing to them, I shot one that was sitting in between explosive barrel it did nothing to it.

So if you dont have ammo that deal cut damage, only way is to spray at it till it dies, or you melee it (not with knife or hammer though, these thing has ridiculous pierce and blunt resistant). You start seeing burning robots and robots with ridiculous gun later though, so hope you dont see those early and try getting the stuff you need fast as you can.