Vampyrisation is the process of converting humans or (less commonly) other humanoid species into vampyres. In Gielinor, unlike most other fictional depictions of vampires, this is not simply the result of being bitten by one. Rather, it is a process that necessarily involves magic, specifically the branch of blood magic known as haemalchemy, and requires refined daeyalt ore as a catalyst. During River of Blood, the player visits a facility that is used for large-scale conversion of humans into vampyres.