A Plague Tale: Requiem is an action-adventure game where you'll be constantly tested. That's especially true if you want to get all those Trophy/Achievements. To get one of these, you must evade killing the guard at the docks in Chapter 4. Here's how to avoid killing the guard and earn the Mercy achievement in Plague Tale: Requiem.
How to escape the guard at the Docks in Chapter 4 of A Plague Tale Requiem
To avoid killing the guard at the docks in Chapter 4 of Plague Tale: Requiem, you must temporarily blind him with the newfound tar resource. Blinding him will give you and Lucas enough time to rush past him and escape without any unnecessary killing.
- Shoot the lock on the drawbridge, and wait for the guard to come down the stairs.
- When he advances towards you, shoot his torch/or him with the tar with the sling.
- Rush past him quickly and head up the stairs on the left.
- Open the door on the right and escape!
If you want to be thorough, you can blind the guard and head to the stairs on the right. There you'll find a chest with a few trinkets. After you take those things, repeat the blinding process and run to the door. Now you know how to avoid killing the guard at the docks in Chapter 4. Be proud, as you've shown pacifism[add link here] one more time.
For more information on A Plague Tale: Requiem, check out Can you get through A Plague Tale Requiem without killing anyone? or Can you fully upgrade all skills & equipment in one playthrough in Plague Tale Requiem?