Felixempra was a charm that presumably aided in granting good fortune to the caster; it was used as the potion-making spell for Felix Felicis. Given how Felix Felicis was invented by Zygmunt Budge, it is possible that this spell was thus also created by him.
Behind the Scenes
- Pottermore revealed that the effects of Felix Felicis cannot be duplicated by a spell. This indicates that Felixsempra can only be used to enchant the potion, but cannot independently be used on a person.
- Wonderbook: Book of Potions (First appearance)