Fallout 4
84 Achievements
1,600
108-139h
What's Yours Is Mine
Pick 50 Locks
30
19.24%
How to unlock the What's Yours Is Mine achievement in Fallout 4 - Definitive Guide
Here's a video from MAKA91 which outlines the location and solution.
Go 4 white lines from the left & down 5 white lines & you'll find 'Jalbert brothers disposal' clear out the enemies & within the warehouse you'll find a desk with a terminal on it & to the left a safe on the floor.
The safe has an expert lock, the terminal is set to advanced.
Pick the safe then hack the terminal, within the terminal you can relock the safe & then pick it again, repeat untill achievement pops.
There is also another location just southwest called 'arcjet systems' that has two more set ups like this, one has an expert terminal & an advanced safe & the other also has an expert terminal but I think it was a novice safe if I remember right. However above the safe is a cabinet with the password for the terminal so this may be the best option for people with a low Bobby pin count or a low lock pick skill.
However, to reach this one
Found a pair of Advanced locks in Trinity Tower (destination of the side quest "Curtain Call"), on the lower floor of the first area the elevator brings you to. They're behind a locked door (or you can drop in thru the ceiling of the broken elevator) - the terminal can re-lock the door as well, but it doesn't look like you can pick it from the inside...
If you have played the previous Fallout games, you will be familiar with lockpicking. To pick a lock, you first need Bobby Pins but these can be easily bought from vendors or found throughout the Commonwealth. Once you have some, find any door or container that is [LOCKED]. You now have to complete a little mini-game where you rotate the bobby pin, then turn the lock. If it gets stuck then the bobby pin is in the wrong place so turn it a bit more before pushing it again. Keep doing this until the lock rotates all the way. This position is called the "Sweet Spot". The Novice locks have a big sweet spot but Master locks have a very, very small sweet spot. Do note that Bobby Pins don't last forever and have a durability limit, that is unless you have unlocked the last tier in the "Locksmith" Perk.
Locks are broken down into 4 types. Novice, Advanced, Expert and Master. You will be able to open the Novice locks up from the get go but you will need to invest in the "Locksmith" Perk to be able to unlock the others. There are plenty of locks to pick in the game, way more than 50 of them. You can't really miss this trophy and it should just come naturally as you play the game:
This achievement will come naturally over the course of your playthrough. Lockpicking in Fallout 4 will be simple to those who are accustomed with its mechanics from previous games in the series and even The Elder Scrolls series. In order to pick a lock though, you need bobby pins. They can be found throughout the wasteland or purchased at various vendors.
Locks will locked (unintentional pun) at the following levels: Novice, Advanced, Expert, and Master. When you begin the game, you will always be able to pick Novice locks provided you have bobby pins. In order to crack higher level locks, you will need a Perception level of at least 4 in order to invest in Tiers 1, 2, and 3 of the "Locksmith" skill.
Once you begin to lockpick, a close-up of the lock will show on-screen where you insert a screwdriver and bobby pin into the hole. From here, you'll need to move the bobby pin left or right while trying to find the "sweet spot," or the position which will allow you to turn the lock open. You need to fiddle with screwdriver and bobby pin simultaneously in order to find that sweet spot. Don't move the tools too quickly though, or the bobby pin will snap and you'll be down one. Generally, practice makes perfect on this mechanic, so don't fret if you're having trouble cracking some safes and doors. Novice locks will provide good practice before you move onto the harder ones.
As mentioned, this should come naturally so long as you invest is those skills detailed above and pick every locked door, chest, or safe you see throughout the wastelands.
If you need a bobby pin for lockpicking, use "player.additem 0000000a 1" to get one.
https://youtu.be/PMm8fUr5b9U