Ancient Shades of Sunrise
Ancient Shades of Sunrise uses a modified form of the D6 Fantasy rules by the now-defunct West End Games.
These modifications were designed to facilitate ease-of-use and creative roleplay with as little mid-game book reference as possible. The spellcasting system in particular seemed overcomplicated, virtually requiring the player to carry an actual spellbook for their character.
Instead it has been replaced by the Power, which relies on a player to roleplay their character’s spellcasting as it fits into their training, their own particular idiom, so to speak. More on that another time though.