Hermetic Space Magic


So I was wondering if there was a Form that could conceivably contain spell effects related to space which one would it be. By the way, when I say space I don't mean solar or interstellar space, I mean things like the spatial size of an object, distance between two points, and the idea that something can be bigger on the inside than the outside shell would technically permit.

I have three ideas though I'm quite interested in hearing what others might say.

Idea One is that it would be an extension of the Auram Form. This is a highly random idea because nothing in medieval philosphy (which Hermetic Magic is technically based on) has space and distance being related to 'air.' But still, I could technically see the expansion into this Form.

Idea Two would be Imaginem, because this is the Form all about Species and from just a pretty quick look on Wikipedia (and as this is not a college paper, a wiki is fine for basic research, lol) medieval philosophers had the idea that the space of objects and its size were all connected to the species of things. So, while this is slightly counterintuitive to a modern day perspective, it seems that making such magic related to this Form might work with the medieval paradigm a lot more easily.

Idea Three is having it be Vim, since Vim is all about power and magic as a pure force and making objects have a bigger size on there insides seems to be a power based thing. I wouldn't really go with this but I could see this as being an option.

As for Technique, Rego seems to be the main choice. Though I could see Creo magic being used to effect size, shape, and space aspects on things that don't normally have such things.

The benefit of such magical effects would lead to chests, pouches, bags that have more storage within despite their outer container size and the idea of doors that lead to rooms that in physical geography would be pretty tiny but in mystical reality are the size of houses and mansions and entire castles. Such magic would probably need something like a Sun duration to be efficiently used, or Year duration so as to last a nice amount of time, or even be a magic item with the effect installed so that the chamber will permanently exist without need for a magus to sustain it.

So yeah, I was just wondering what others thought on this topic. :slight_smile:

You mean like the old D&D Bag of Holding?

I'd do it with regiones, that inside the bag, chest, room, etc. is another regio that is larger than one would expect. If I wanted magi who could make such items, I'd have them invent magic that could create regiones. I think there are Creo Vim guidelines for something like this in Realms of Power: Magic.

Matt Ryan

This idea pops up every once in a while - and it's one of the things that hermetic magic really isn't much good at.

Common suggestions include regiones and glamour (eg the Bottomless Bag of MoH, p. 126).
House Mercere also seem to have half-a-trick with ReTe, but that's more like warping space to connect 2 locations that are normally apart (Hermes Portal, Mercere Portals).

But in general, I'd say that that's somethign we should consider just accepting that Hermetic Magic can't do.

A Mystery would serve best for something like this I think. Though possibly if you were to try and nail down a Form, I'd go with Terram as things are manipulated on the earth, including the space of it. If a Mystery were developed it would likely require a total of a Characteristic, (New) Ability, and then various others, like Terram and possibly Rego or even Muto.

Granted it's not a great fit. Requisites help it work better. But looking at the high power spells such as Hermes Portals, it uses Terram.

It's never been made clear whether making a bag larger inside than it is outside is already part of Hermetic magic or not. There is one example in MoH, but the item in question is also the result of experimentation; though MoH does not specify whether experimentation was the key to an otherwise unachievable result or not. So I guess it's ultimately up to the individual troupe.

If you do decide to allow vanilla Hermetic magic to manipulate space it in your saga, I think that the most obvious guideline is that for the various "unnatural" effects in the various Forms (like Terram or Aquam or Animal, but I see no reason why one should not extrapolate to most Forms). This means that to create bronze chest that is larger inside than outside would be Creo Terram, and to alter an existing woolen cap to be larger inside than outside would be Muto Animal. The cost of such "unnaturalness" is generally one or two extra magnitudes. Making a bag larger inside than outside would then be a Muto effect that "changes the target in a very unnatural way".

Alternatively, you could say that these types of effects are not yet Hermetic. Note that in general it does not go against the Limits of Magic, so even if it's not yet Hermetic, it would be at most a Major Breakthrough. Faerie Wizardry, and in particular Conjure, can specifically achieve these results if I remember correctly, so that could be a source of Insight.

Another type of space manipulation, creating a "wormhole" between two points, is probably not yet (entirely) Hermetic: that's after all what a Mercere portal does. Again, Mercere portals could be a good source of Insight for a Breakthrough.

An alternative is to enchant the space to shrink everything within it. An example is the Granary Chest on page 69 of Magi of Hermes. Shrinking everything is a pretty difficult thing to pull off, it might be just as easy resource wise to look for a way to do the rego terram wormhole teleport thing or glamour magic

Nothing new to add, but here's a link to an old discussion where some interesting points were made: https://forum.atlas-games.com/t/magic-of-spaces/4677/1

Matt Ryan,

While using the rules and descriptions of regiones make sense, its the closest in-game mechanics we have to the idea of bigger on the inside than the outside, I don't feel comfortable saying that such magics is clearly a regio. To me, regios are the realms within the world, the places where you go for adventure or establish your covenant or battle some enemy that has made themselves at home in a regio.

Plus, having Vim be the way of the magic means its a single type of magic - I kind of like the idea of having the other Forms have some part to play in it.

But yeah, using regiones as you suggest is a great idea as a basis for how things would look in game terms.


I think the idea comes up so often is that its one of those iconic mystical abilities that many people identify as a purview of mighty wizards.

I mean those who come from D&D know and probably love the iconic Bag of Holding. Those from say White Wolf Mage (in all its incarnations) know about The Space Sphere/Arcana and how it can bend locations. And those from Harry Potter see wizard tents and wizard chests and wizard stuff.

I'm all three, lol, which is why I kind of want to find a way to mechanically allow them in the game. Though I am not just saying I want to hand wave the issue away and say "it always existed", I'd much rather have such magics be developed in play through breakthroughs and analysis.

Now admitedly I want to include it in the current array of Techniques and Forms, I don't want to create a 'Astro" Form which handles such things - that is a cop out and not at all keeping in the spirit of Ars Magica. :slight_smile:


I think it being a Mystery sounds really cool, especially if its the players that are the ones coming up with the magic.

Speaking of the Hermes Portals and such, I never understood why its a Terram effect. I mean I know its not truly Hermetic, its mostly still Mercurian. But all the other Rego magics are based on the Form of that which is being moved - So a RegoHerbum spell might move plants and a RegoCorpus spell can move humans. But then out of nowhere a RegoTerram ritual can move plants, humans, animals, and earth. I guess they needed to figure out where, and it being a breakthrough means it only has to roughly fit Hermetic magic, but still - the completionist in my finds it difficult to accept. hehe


Yeah, you make a good point. It is not one of the Lesser Limits of Magic (which in all honestly I hate, and wish to break most of them in-story as soon as I can, lol), such spatial magic is never really mentioned.

Your idea has a lot of merit. It means that once developed it becomes a magic that nearly naybody can do, no matter what particular Form they have mastered. The plant master can use his Herbam score to make a woven bag of wood, the animal master can use his Animal score to make the pouch using lamb skin, the Terram master can use stone and metal to create a bucket with a bigger inside. Such things would thus become much more common than if it was purely Vim.

I also like the idea of making it a Breakthrough that would occur in play, being the focus of story and adventure and the difficulty in finding other forms of magic that might make such a thing much easier. Heck, trying to negotiate with the magi of House Mercer to study their portals could be a saga all of its own - and thus would make the eventual breakthough all the more sweeter. hehe

So yeah I think such an idea would be really cool a really nice way to go about doing it. It would have some changes to the fabric of the Order of Hermes which I also would like. Example, having the ability to make a single tiny closet open up into a mansion the size of a King's palace would enable magi to hide themselves much easier from mundane authority.

I could also see further breakthoughs from this study resulting in magics letting one create regiones, which I would summize as to be a free standing example of the above larger space, one that exists without the need for continuing mortal magic. (After centuries of living in the mansion that one can enter through a closet, a magus might discover that the closest itself no longer seems to be the thing that sustains the mansions larger than outside size, it has taken on a stable existence of its own and is now a part of the Magic Realm, which could cause all sorts of interesting saga adventurers).

Erik Tyrrell,

When I saw that item in Magi of Hermes I got a big smile on my face. I thought (still do actually, lol) that it was a great item with a very cool method of doing what it was doing.

I could totally see the difficulty of that item and the nature of how the objects return to normal being the action that leads to the magus trying to research a new way of doing said magic. In the attempt they could study such shrinkage spells, which could lead to all sorts of fun stories - "parens I shrunk the apprentice" and stuff. hehe


Nice, thanks for providing the link to this alternate thread. It will be interesting to see what was discussed previously to see if there is any cool ideas that I could take for my own. :slight_smile:

Looking at the thread makes me realize two things - I will need to read Conjure to see if there are ideas I can shamelessly take from it to find a mechanical basis for the idea I have and 2) ever since reading in Hedge Magic the thing about Fortune I have wanted to find a way to include it without doing something like adding an entirely new Form. (Though this is a topic for another day, its only related to this thread cause of the informative link you provided.)


I still think the idea of having it be Imaginum might work. It fits the medieval paradigm, the various ancient philosophers all wrote about how size and shape and distance were all part of species could really work. I would probably require Requisties from the material being changed (so to make a chest of holding one needs to add a +1 Terrum requisite, for example) as well as various unnatural or extended or detailed magnitude bonuses to make things much more difficult, but still.

Though I will wait and see and maybe somebody much more knowledgeable on the topic of medieval species will comment, either telling me how wrong I am (lol) or how its an intriguing thought, hehe.

The alternative is to make something which shrinks the objects so long as they are inside it.

That's what I did. Use an inverted version of Object of Increased Size, add an extra magnitude for twice the effect (1/4 each dimension for a total of 1/64 of the volume/weight). Reduce the duration to Concentraion, have the item maintain it, and add infinite uses - for a total effect of MuTe 30. Enchant this on a bag and everything that touches the inside of the bag is shrunk while it is in touch with it. Only problem is the ammount of casting requisites to cover all possible items (Herbam, Animal, Aquam) which makes this rather hard to enchant.

I would agree with this.

I've played in a 4th ed game where there were several 'extended' forms - Spiritus (regarding spirits and ghosts and an umbral realm); Animus (regarding souls, Angels and Demons); Ingenium (regarding ideas and experience points!); Spacio-Temporis (regarding time, space, regios, etc); and Empyrius (regarding outright creation - God).

The SG reserved most of these forms to his exclusive use, (our party helped bring Animus to the Order, which had major ramifications) but had previously run a game where Spacio-Temporis had been discovered. The big problem he had with it (apart from enabling time travel, which was really stupid), was the access to magic to affect regios. As soon as PCs can change regios, you open up a large can of worms and the whole 'feel' of the game changes.

So, if you want actual warping of space rather than a shrinking/enlarging effect I would make it a separate virtue and supernatural ability (major or minor?) so it can't do really big effects but making bags of holding, or cupboards with labs in can be done. Not hiding entire cities - go find a regio and build a city in it.

Clearly, as we keep seeing threads about it in here! :wink:

I thought the D&D-kids were using Handy Haversacks these days?
And I could have sworn the MtA Sphere was called Correspondance?
And yes, things being bigger on the inside than on the outside is a very old idea, though one I must admit I more strongly associate with the fae than with wizards.
And lo and behold! 2 suggestions were offered! Regiones and Glamour Magic (well, I think it's called Conjuring if you use the faerie Art), solutions more easily available to the fae. :slight_smile:

Which is exactly the way to go for Ars Magica! :slight_smile:

I would just add a small canon reference to the topic:

ARM5 Covenants - p118: Free Supernatural Vitrues: Boundless
'This effect outside of the scope of normal Hermetic magic, but it might have a non-Hermetic or faerie origin.'

Sooo... you can expand Hermetic Magic understanding on Rego Terram Art or find a non-Hermetic Mage with relevant talents or get a faerie friend who can do it, just as it has been said above me. :slight_smile:

I think the take was not that you are transporting the things that pass through the portal, but instead you were bending the earth so that the two sides of the portal are adjacent, (but that could just be my take).

BlackLiger and Toa,

I could see using the idea of shrinking an object to fit within a normally sized space as a sort of begining point to the effects I want. I just don't want it to be the end point. But it definitely is a great idea to start off with and can have a lot of uses that aid in the development of covenants, magi, and the Order itself.


It seems nifty on a general whim, but having additional forms just seem to change the core assumptions of the game too much. It does sound cool as a game concept though, I totally could see having lots of fun in such a game.

I have always felt that most things should fit into one of the Arts of Hermetic Magic, and if that doesn't work represent it by a Hermetic Virtue that modifies Laboratory activity or adds a slight sideways effect. But always use the Arts that exist as the basic concept.

Related to Spacio-Temporis, I never understand the concept of the restriction on seeing the past. I think being able to look back into the past is a nifty power that should exist. I get the future, it is still fluid and open to freedom, but the past being sent in stone should be viewable. I could see all sorts of restriction on what is the 'present' and what is the 'past' but I think it could exist. (Heck it could lead to an encounter, the player magi use magic to scry the past and then get to play the grog or companion level characters as they go about what was being scryed - what the characters do is what the characrers in the present get to know about. hehe)

I like the idea of being able to use magic to extend Regios, but I also really like the fact that they are completely natural occurances that exist as part o the world's nature and not something humanity just makes whilly nilly. I don't mind the idea of making a pouch that is say an inch in diameter open to a space that is a foot, or a small one room tent open to something with three rooms, but when you get city sized, no regio's must be use.

So yeha, I totally agree with you. I think its a matter of scale - small scale expansions can exist using Hermetic magic but if you want a world inside a closet than you have to find a huge epic legendary adventure quest to bind the regio to the closet door. hehe


I like the fact that there are a bunch of names for the same old thing, even in a single game like D&D.

Oh, yeah, your right it was called Correspondance. I could have sworn it was called Space, hmm, maybe I was just thinking Awakening, which has it as Space. lol

I looked up conjuring, it just has one line about the bigger inside thing, and while its interesting I would never use the Fae based image magic as a core fundamental Hermetic trait.

Oh yeah, magical breakthroughs as in-game story developments are the way to go for most sorts of additional magic. If a player spends many sessions dealing with something, the least that can happen is they get some benefit to recreating such magic using the Hermetic Arts.


Little references like that in books always bring great smiles to my faces. Such concepts support adventure and interesting story developments, and that is always a really great thing in my point.

Erik Tyrrell,

I never thought it in that way, I really like that. I am going to totally use that as the reason why its in Terram, it really is that awesome. Thanks for mentioning it, cause its really an awesome way to look at it.