How to unlock all 4 weapon slots in Borderlands 3

There are a total of 4 different weapon slots in Borderlands 3, but when you begin the game you can only use two of them. This can be a little tricky when combined with the fact that you can't really carry a lot of ammo early on in the game, so it's a huge relief to be able to unlock the third and fourth weapon slot so that you can use four different weapons, and potentially four different ammo types.

The method for unlock all the weapon slots in Borderlands 3 is a bit boring, and the answer is to just play the story mode / main quest. The weapon slots are reward for certain quests, which we will take a closer look at below, but keep in mind that this will contain minor spoilers.

Unlocking the third weapon slot

You unlock the third weapon slot in Borderlands 3 during a mission on Promethea. The mission is called Taking Flight, and it's fairly early on in the game. Most players are probably around level 7 or 8 by this point. Just follow the main story quests and you will get this pretty soon.

Unlocking the fourth weapon slot

The fourth weapon slot in Borderlands 3 comes a bit further into the game, and you can expect to find this at around level 20 - 22, depending on how much you like to do side missions. The quest mission for the fourth weapon slot is also a mandatory main quest on Eden-6, and the mission itself is level 20.