Quick example of how to improve a Magi’s lab in Ars Magica

I was initially baffled by how to spec and then alter a Magi’s lab in Ars Magica. These are my cheat notes for how it works… 

A basic rule is for every improvement you want it to make in a lab it probably requires an investment of a season to make the change, and first an additional space. The remaining space is represented by the size less the consumed space, and the process of Refinement adds more space to a lab by reorganising the current content. Essentially the Magus can reorganise the content many times but there is little benefit unless the new space created will be used for something significant. 

This means that a season is needed to refine a lab first, and then whatever enhancement. So most improvements need two or more seasons. In more detail…using an example helps. 

Firstly, a brief description of the initial lab should be written. This fluff allows a common view point for the starting conditions and a basis for expansion.

“The laboratory of Zharkune the Necromancer is located below the ground in one of the Covenant’s cellars. This is accessed by a secured stairway from an antechamber on the tower’s ground level aside the main corridor. Both the antechamber and the downward stairwell are secured by heavy wooden door, the inner door bearing Zharkune’s sancta marker. Inside  the cellar is cold and dark, with no natural light which insulates the lab against outside noises. The lab is standard size, with a two small storage chambers to the north, a side reverie for reading, and an unused but furnished sleeping chamber to the south, as Zharkune also keeps a larger residence in the upper levels of the tower. The ancillary chambers are not considered part of the lab proper, but could be converted for use in the future.”

The second task is to set the initial conditions of the lab, and those are based upon the construction, physical environment, and resources of the covenant. Some labs will start very plain with no special features, but many should start with altered characteristics. Further if the covenant has pervasive aspects like a regio or in an extreme temperature then this should be accounted for.

Laboratory of Zharkune the Necromancer – Starting characteristics. 

Working scores: +2 Safety, +2 Aesthetics, +1 Upkeep, -1 Health, +1 Terram, 


  • Well Insulated (behind two doors and underground): +1 Safety, +1 Aesthetics.
  • Subterranean (cellar): +1 Upkeep, -1 Health, -1 Aesthetics, +1 Terram. 
  • Guard (who protects the outer door): +1 Aesthetics.
  • Superior Construction (a conjured tower): +1 Safety, +1 Aesthetics

Laboratory of Zharkune the Necromancer – Modified characteristics. 

After a brief year (a season of refinement and a season to invest each of the two properties) Zharkune’s lab has become specialised to his tastes. 

Working scores: +2 Refinement, +2 Safety, +4 Aesthetics, +1 Upkeep, +1 Health, +1 Terram, +1 Corpus, +1 Creo, +1 Warping, 

Additional attributes:

  • Specimens (human body parts): kept for study and for reanimation. +1 Upkeep, +1 Aesthetics, +1 Corpus.
  • Preserved (a magical storeroom): which keeps content immune from natural decay. -1 Upkeep, +1 Warping, +2 Health, +1 Aesthetics; +1 Cr.

Advice for lab creation

A common example – a covenant tower created with a magical ritual or sources from some other supernatural source should start with the Superior Construction quality.

Also if the wizards have the option it is far better to create labs which are larger than the standard; meaning a positive size attribute due to initial construction. This is because each new aspect or quality which is added takes up a virtual point of space which is directly linked to size.

Then the players should discuss is any characters wish to gain highly customised aspects (such as a bottomless pit or sentient lab) as this will guide the flavour of the lab going forward.



Terram Magi, the Societas Guernici, Covenant of Hedyosmos

I’m gathering material for a new Magus, who I wish to focus on Terram magic. This post is a place to gather all the points of reference into one place so I can find the material later, and also to share the existing sources for Terrae Magi.

Initially the Magus was to be based only within the current 5th edition rules for Ars Magica, but as I read the wider source books and community written content – the core approach doesn’t sound as deep or plentiful as the “Magi Terrae” which have been detailed elsewhere. I’d like to add another line of Terram orientated

Overview of Sources:

  1. Houses of Hermes: True Lineages (HoH:TL p68) mentions that Guernicus (the founder of the House and first Quaesitor) was also a passionate Terram Magus. It does not provide much more detail, except to say that the tradition is small and still in existence, and not a “proper” Mystery Cult in terms of the source books for Ars Magica. It implies the group is an association of like minded wizards who share a common interest and may share discoveries.
  2. The Sundered Eagle: The Theban Tribunal (tSE p67) gives more details on a particular sect of the society, detailing that particular sects link to the Greek Titans and their center of power within the Covenant of Hedyosmos. It contains a brief overview of what a Terram magus of this line might be like. It also briefly explains the link between this style of earth magic and the cult of the dead. This is a useful core rules source as it also contains the initiation scripts and suggestions for powers which are appropriate (such as Elemental spirit familiars).
  3. Jarkman’s Terrae Magi / and Societas Guernici: includes a rule-set for making characters who are members of two different lines of Guernicus, the detailed Mystery Cult, new Terram spells, and a wonderful set of lore.
  4. Hermes Portal, Issue 14 – Omnibus Grimoire Terram: includes some wonderful spells, including almost a match to a “set of steps” which was an effect I’ve drafted but not as yet finished.

Thoughts on Sources:

There is a little contention between these sources, which is to be embraced. The sources for the official RAW line clearly detail that Guernicus founded a society, and not a mystery cult, yet much of the material is based upon mystery cult structures.

The initial section in HoH:TL suggests that the wider organization is open and welcoming, but also reads as if more restrictive when the members of the associations are role-played. That makes good sense and dovetails with the approaches from The Sundered Eagle and Jarkman’s pages.

I would like to see the Terrae Magi become a wider and more open association, which then contains these clutches and cults within it. The name “Students of The Stone” is very evocative and suitable. I don’t see a need to dispute any of the sources above, and would suggest a character in-play could become known as a “Student of the Stone” and be friendly with these traditions without disrupting their own path.

I’d like to detail an alternate path, which stands separate from these sources, and uses Scandinavian/Norse roots instead of Greek.

Hopefully more on that soon.