When you first leave the vault in Fallout 4, you'll notice there's a locked container at the end of the level. It has a gun; a really good gun, by the looks of it. One problem: there's no way to actually open the container so early in the game. Unless, of course, you know of a loophole.
Normally, in order to open the container in the Overseer's office of Vault 111, you need "master" lockpicking, a perk you can only get once you're level 18 (provided you have enough perception). There's no way to have this build so early in the game, so it seems that Fallout 4 wants you to come back and open the lock later, once you've earned it.
Here's the thing: you don't NEED to wait until level 18 to open that container. You don't actually need the master lockpick perk. You don't need no damn bobbypins to open the lock. All you need is Dogmeat, who you can meet a couple of hours into the game (if that). Here's how:
Once you have Dogmeat, return to the Overseer's room. Tell Dogmeat to fetch an item for you. He should bust open the container, and hand you the Cryolator gun waiting inside. Ha! Anyway, I walk you through the entire process in the video above, if you're curious.
So, why would you want this gun in the first place? It's really powerful!
Some people are calling it the best gun in the game, and if you watch the video, you'll see why. The Cryolator appears to one-shot-kill many enemies by freezing them solid. That said, if you get the Cryolator early in the game, you'll probably be pressed for ammo. It comes with at least 200 rounds (check Dogmeat's inventory, if you can't find them), and purchasing them from vendors is a tad expensive. But that's OK, really. Great as the gun is, you'll probably want to save your bullets for strong enemies. If you're flush on cash, though, I've seen the vendor at Drumlin Diner carry the ammo.
Happy freezing! And if you're having trouble getting back into the vault, remember: there's the elevator button in a booth near the entrance.