Image via Warner Bros. Interactive Entertainment Turtle Rock Studio’s latest game, Back 4 Blood, returns to the studio’s roots for cooperative shooter action. Players team up to take on the Ridden, a mutation caused by a virus that Back 4 Blood’s Cleaners specializes in exterminating. Along the way, players amass Supply Points to compensate for their efforts, but what can players use Supply Points on? Supply Points are Back 4 Blood’s currency system and can be used at the Supply Line Provider to purchase cards and cosmetics. Each of the game’s supply lines has eight levels that players must complete from start to finish to earn all the rewards. Players cannot randomly choose rewards. Related: How To Unlock Characters In Back 4 Blood Some Supply Lines Focus On Upgrading A Single Attribute From A Character’s Kit. For example, the furnace supply line improves player constitution with offensive and defensive ability cards. Those who wish to optimize their deck for a specific playstyle should read the description of each supply line before spending their hard-earned points. Back 4 Blood is available now for PlayStation 4, PlayStation 5, Xbox One, Xbox Series X | S, and PC starting at $ 59.99. To learn more about Back 4 Blood, be sure to look at other Pro gaming guides, like All Character Abilities in Back 4 Blood.