Archaeron is a fantasy system similar to Chivalry & Sorcery, for which only two rulebooks were ever published.
[1] Mage, the first book, is a fantasy magic system with complex rules for spellcasting, creation of magician characters, and various types of magic and spells.
[1] There are three types of spellcasters: Psychics (divided into Mediums, Seers, and Natural Psychics); Magic Users (Conjurers, Thaumaturges, and Enchanters); and Theurgists ("cleric" types: Symbolists, Mystics, and Necromancers).
[1] Warrior, the second book, is a fantasy combat system for medieval European-style combat, with rules for creation of warrior characters; detailed weapon skills; melee, missile, and mounted combat; wounds and healing; etc.
[1] The digest-sized 48-page book Warrior was written by Backhaus with Jan Vrapcenak and Richard Fietz, and published by Archaeron Games Ltd. in 1981.