Yes but they only give two examples and fall very short on making it usable. There isn't really a system behind it. Rituals and Relics I've got and I think it's fairly good.Jadeite said:There are also rituals called Incantations in Unearthed Arcana:
http://www.d20srd.org/srd/variant/magic/incantations.htm
jdrakeh said:If you're not adverse to looking further back than 3x, there was an excellent RoleAids box set called Arch-Magic produced for AD&D that includes rules for powerful ritual magic (the likes of which evil sorcerers in Conan stories would likely indulge in).