Sorcery is a branch of magic where the magic user will summon spirits and bind them to their will. Sorcery is a very unstable branch of magic and very unpredictable. However, if done correctly, sorcery would allow the magic practitioner to become more powerful due to the use of the spirit, however if performed incorrectly, or the practitioner is not powerful enough, the spirit may end up possessing the body, becoming a Shade. While on his second visit to Ellesmera, Eragon asked Oromis if he could learn how to summon spirits. Oromis said he would stay true to his word but pleaded with Eragon to choose another branch of magic as sorcery was too perilous and would not serve the Riders' cause.