As you play through Back 4 Blood, you’ll be forced to engage with a card system that tries to make each game unique.
It’s great, in theory, but it’s not explained particularly well and perhaps makes things a little more complicated than they need to be. But still, if you’re going to be playing Back 4 Blood for any length of time, you’re going to want to unlock as many cards as you can and put together a deck that suits you. So: how do you get more cards in Back 4 Blood?
To unlock new cards in Back 4 Blood, you first need to earn supply points. They’re earned by simply playing the game, though be aware that the difficulty you’re playing on matters. On Recruit difficulty, for example, supply points earned are cut in half, while on Nightmare difficulty you get an additional 50%.
Once you have some supply points, you can start spending them on supply lines. Access the supply lines page by either interacting with the NPC near the garage, or opening up the menu and navigating to supply lines with the shoulder buttons. There you’ll find one or more supply lines, full of cards and cosmetics for you to unlock with your supply points.
Each card and cosmetic in a supply line costs a varying number of supply points to unlock, and they must be purchased sequentially. Compete a supply line by purchasing everything, and another supply line will be unlocked. Needless to say, it’ll be quite a while before you’ve unlocked everything.
Once you’ve unlocked some new cards, be sure to put a new deck together that makes use of them, or edit one of your old ones. After all, unless they’re in a deck, they can’t be used.