Spec Ops: The Line
50 Achievements
15-20h
A Line, Crossed
Choose vengeance.
22.2%
How to unlock the A Line, Crossed achievement in Spec Ops: The Line - Definitive Guide
For this achievement, choose to open fire on the civilians. Proceed on a bit and the achievement will pop. You can reload checkpoint and get the other decision
Video has both achievement decisions
If you missed either of these achievements during your playthrough goto mission select and choose Chapter 13, and proceed to the part where you must run and find your second team mate, here you will see a cut scene after which you have a choice to make.
A Line Crossed
For this achievement you need to open fire on the civilians in front of you and proceed on through the camp and this achievement / troph will unlock.
You can reload checkpoint to get the other achievement
Video Shows Both Achievements that are unlockable at this point
http://game-play.tv/video/H2OWB95BHM28/Spec-Ops-The-Line-A-L...
To unlock this one, open fire into the crowd of civilians when given the opportunity. Proceed forward and as you approach the exit the trophy will pop. This one you can reload the checkpoint and choose the opposite decision for the other trophy.
At the end of chapter 13 you will come to a disturbing scene. After you find out some really bad news you can choose to show restraint or succumb to vengeance. You’ll get this trophy if you go crazy and kill the citizens. After the massacre exit the chapter and this bloody trophy is yours.
If you need additional information or just prefer visual aids then refer to A Line, Held
Chapter 13, you will come to a part where you must find one of your partners in the town. After a cutscene, you will be surrounded by a large group of civilians. You can choose to shoot the civilians causing them to flee or shoot in the air.
For this achievement, open fire on the civilians. Once you kill a few and the rest run away, you will unlock the achievement. You can reload checkpoint and get the other decision or wait for your 2nd playthrough of campaign.