Spec Ops: The Line
50 Achievements
1,000
15-20h
The Human Factor
Kill an enemy by tagging him with a sticky grenade. (campaign only)
20
How to unlock the The Human Factor achievement in Spec Ops: The Line - Definitive Guide
On the right by the jeep are sticky grenades. Collect them then sneak to the left. There is a guy with his back to you. Stay in cover and tag him with a sticky. Simple.
I also killed the other two soldiers with the same explosion.
To unlock this trophy you need to tag an enemy with a sticky grenade. A sticky grenade is exactly what it sounds like; this must be “Saving Private Ryan” reference (sticky bomb?). To Throw a sticky grenade you must first select it with the either or on the D-pad. Once you have the "center" grenade selected lock onto an enemy by pressing and holding , release to throw the grenade. You won’t get a chance to use these sticky grenades until chapter 6, but during that chapter and onwards there are countless amounts of times you’ll get a chance to do this. Once you achieve this “sticky” kill the trophy will pop.
If you need additional information or just prefer visual aids then refer to FLIPADELPHIIA’s video below.
The first time you pick up stickies is in Chapter 6, and you can get the achievement as soon as you pick them up if you're careful. You simply have to aim and toss it at an enemy and hit him. You can hold to view where the grenade will be tossed. Once you hit him, he will kind of do a little panic dance and then blow up.
During Chapter 7, there is a guaranteed spot to get this one. You will eventually come to part where you have to shoot out a big glass in order to continue. After that you rappel down into a desert area, and you will come across several guys standing around, not noticing you. Before firing at them, look for a sticky grenade crate right as you enter the area. Crouch down and aim the grenade at one of the guys, making sure to stick him.
https://www.youtube.com/watch?v=G9elX1xFAh4&feature=player_detailpage#t=15 s