Blood Code is a flexible Class system in Code Vein. Instead of having regular starting classes and locked abilities, Code Vein provides freedom by allowing players to level up different Blood Codes simultaneously, and swap them on the fly. Blood Codes affect the player character's actions and Gifts (Magic) available, providing optional approaches for difficult areas or bosses and the capability to master multiple builds.
Code Vein Blood Codes
For the demo at TGS, the Blood Codes were not interchangable, but the developers revealed players could opt between more "warrior-like" or "wise-like", etc. They also implied players would be able to change these at any time, elinating the need to respec.