Ars Magica is a role-playing game set in Mythic Europe, a quasi-historical version of Europe around AD 1200 with added fantastical elements. It typically centers on the lives of Magi, powerful wizards belonging to the Order of Hermes, and the various mundane folk in their lives. While several details about the world change, sometimes drastically, from edition to edition, the same basic premise applies: the Order is a secret society in a world that believes in magic, founded by the apprentice of a wizard who first developed a unified magic theory and a general defense against magic, the Parma Magica. There are twelve Houses (with a missing thirteenth), each focusing on a particular area of study that the House founder excelled in originally:Bjornaer: Shapeshifting magi who can change into form of their "Heart-Beast" (or, in the case of an inanimate, natural object, a "Heart-Shape"). They are descended from a Pomeranian Bear-witch name Birna and practice secret magical rites at their Domus Magnus Crintera every twelve yearsBonisagus: The Founder of the Order, though his apprentice Trianoma did most of the leg work. Originally wrote the Bonisagus Magic Theory, which is the magic system the book uses and that all Hermetic Magi are expected to know, if not use. Those who consider themselves Followers of Bonisagus are more interested in the study of magic; the Followers of Trianoma are more politically-minded. Either way, they have a natural prestige within the Order due to their Lineage.Criamon: Magi who pursue The Enigma as the path to true wisdom and power, often prone to prophecy and using unusual logic to solve puzzles and riddles. Most insist that the Order is doomed on one level or another.Diedne: Druids who were virtually wiped out during the Schism War and tend to be terminated with extreme prejudice even now; early editions simply mention the house as existing at one point, but they provide no information beyond "You cannot play a member of House Diedne" and a Flaw that means Quaesitors suspect your predecessors of being Diedne. Later editions provide rules for Diedne Magic, and detailed history regarding the causes of the Schism War itself (suspicions of human-sacrifice and devil worship, coupled with the house's insular and secretive nature).Ex Miscellanea: Originally created as a "rival Order" to the Order of Hermes, but it didn't quite get there. Most of its mages only nominally practice Hermetic Magic, and is home to several "converted" hedge-wizards. Most (but not all) members do practice Hermetic Magic, albeit coloured by their earlier training, but as members of the Order they are taught the Parma Magica.Flambeau: Battle-hungry pyromaniacs who love fire and warfare; probably the most mercenary of the Houses. Later editions have down-played the pyromania and homicidal, with mixed reaction from fans of the house. Many members of the house specialize as Hoplites (Guernicus: Also known as House Quaesitoris; Order-keepers and judges, effectively the police. In later editions Quaesitors may come from any House, but Guernicus magi still tend to predominate due to their specialization in Intellego and Terram magics.Jerbiton: Socially-oriented mages who love things like high society, the arts, and the Church. Most of the House's apprentices are acquired from noble houses, and sometimes even retain their mundane lives once out of apprenticeship.Mercere: Primarily messengers and the Hermetic equivalent of the Pony Express; most of the House is comprised of mundanes. The Founder Mercere lost his Gift and took up the useful position of messenger. The Gifted members of House Merecere tend to focus on the arts of Creo and Muto and frequently possess the Mercurian Magic virtue.Merinita: Split into two camps the same way Bonisagus is, with Followers of Merinita focusing on Nature magic, and Followers of Quendalon focusing on Faerie magic. This gives them some trouble, as molesting the Faeries is against Hermetic law. In addition to giving them access to unique RDT parameters, Merinita magi are less inconvenienced by Faerie Auras than other Magi.Tremere: Rigidly hierarchical and focused strongly on various aspects of war, especially strategy, and notorious for moving sheer numbers across tribunals to gain the majority vote in order to block unfavorable laws from being passed. They operate under strict codes of dominance and submission, and often not considered trustworthy by the rest of the Order due to their trying to take over the Order. They are usually written as the primary instigators of the Schism War.Tytalus: The Trickster House. Tytalus philosophy states that only conflict can inspire growth, and so they constantly test themselves (and others, whether they like it or not) in various ways, sometimes referred to as The Game. This eventually led to the House's corruption when they tried to outwit the Devil, resulting in widespread diabolism.Verditius: Natural artificers who are inept with Formulaic magic, requiring casting tools where other magi of the Order need none; they produce most of the magic items in the Order and are the beating heart of its economy.The Order of Hermes itself is richly political, with laws governing how Magi must conduct themselves toward each other while at court (Tribunal) and just in general, with secrecy and the right to power being primary tenets of the vow taken by mages at the completion of their apprenticeship.It was one of the first examples of a Troupe system: early editions recommended that the players collaborate to create the campaign world and story. Each player would have an opportunity to be the Story Guide, and each player would have more than one character, so that if they felt their main character would not go on an adventure (for example, if they were busy with their research) a secondary character may be used. The game was developed by Jonathan Tweet and Mark ReinĚHagen of World of Darkness fame and if you look, you will find traces of Ars Magica in the Classic WOD - particularly the Order of Hermes mages and the Tremere vampires. The magic system of Ars Magica is generic, based on a combination of Forms and Techniques (to create fire, you'd use the form Ignem for fire and the Technique Creo for create together) and very intuitive. It's also one of few magic systems that allowed for spontaneous spellcasting, allowing the player to use magic off the top of their head to perform specific tasks, rather than limiting magical ability to a shopping list of immutable conditions and effects.Had an unsuccessful Kickstarter towards a computer game version.
Ars Magica provides examples of: