Containers, Spell Types, and Circles

Here are all the current proposed clarifications and revisions for container targets. There is a question at the end.

Container Targets

Spells with "container" Targets, including Circle, Room, Structure, and Boundary, can work in one of two ways.

First, they can affect any valid target within the Target container at the time of casting, and continue to affect those targets even if they leave the original target area, and even if the target container ceases to exist, for as long as the spell lasts. It does not affect anything that enters the target container later, even if the spell is still in effect.

Second, they can affect any valid target within the Target container during the spell's period of effect. In this case, a valid target that leaves the container ceases to be affected by the spell, and a valid target that enters (or re-enters) the container is affected, until it leaves or the spell expires. In this case, the spell ends if the container ceases to exist, even if it has duration left.

The way that a particular spell works is fixed when it is designed, and cannot be changed by the casting magus, although a spell working in one way is similar to a spell that is identical apart from working in the other, and so knowledge of one gives a bonus to inventing the other.

For example, a spell to put pink dots on people's foreheads with Target: Room and Duration: Moon could work in two ways. In the version that works in the first way, everyone in the room (on whom the spell Penetrates) at the time of casting gets a pink dot on their forehead, and this pink dot remains on their forehead until the new moon and full moon have both set, no matter what happens to the room. In the version that works in the second way, anyone who is inside the room (on whom the spell Penetrates) until the new moon and full moon have both set gets a pink dot on their forehead, even if they were not in the room when the spell was cast. When they leave the room, the pink dot disappears, although it reappears if they go back into the room. If the room ceases to exist before the duration expires, the spell ends early. These two versions are two different spells, and a maga who wants to cast both (and cannot reliably cast them spontaneously) needs to create two spells.

Being Inside a Container

The standard Ars Magica rules use an intuitive definition of "inside" when determining whether something is within a container target. A person standing in the centre of a 1 pace diameter circle is inside the circle; someone who happens to be standing directly above it three floors higher is not. A person standing on the battlements of a castle is within the Structure, but a crow flying over the walls is not. If your troupe needs a more precise definition, you can work something out, and nothing should break.

Persistence of Containers

The standard Ars Magica rules use an intuitive definition of whether a container still exists to be the target of a spell. If the same container still exists, then the target still exists. An island does not cease to exist when the tide rises or falls, unless a causeway joins it to the mainland at low tide. A room does not cease to exist when the door is opened, but a room inside a tent does cease to exist when the tent is packed away. Containers can move if they are still the same thing while, and after, moving. Note that certain choices of container make spells vulnerable: if a Room is just a tent, the spell can be ended by collapsing the tent, while if a Boundary is just a fence, the spell can be ended by pulling down any part of the fence. Containers can get larger or smaller, but spells do end if the container becomes too big for the spell to affect.

Circles and Boundaries require some extra comment. A circle is a different circle if its size changes, or if it is transferred to a different surface. Circles are very vulnerable, which offsets the power of Ring Duration and Circle Target. If a Boundary is nothing more than the thing marking the border, then it is as vulnerable as a circle, and cannot be moved, altered, or expanded. If a Boundary is something like "the waterline of this island" or "the wall around this covenant", then it is much less vulnerable, and may change with natural changes in the thing.

Here's the question. The above clarifications change the rules for Circle. Under this proposal, type 1 Circle Target spells are not ended if the circle is broken. I don't think this change will require any changes elsewhere in ArM5, although I could be wrong, and I am inclined to think that it is worth making the change to maximise the consistency with which different targets are handled. It would require a small change to the description of the Circle Target. Comments?

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T:Circle D:Sun/Moon buffs for your grogs become really good suddenly. I can't think of anything it breaks mechanically, though, no.

I really like this additional level of clarity. My recommendation is to create terms to define the different types for ease of reference.

I propose something like Target: Room (Space-Anchored) and Target: Room (Target-Anchored) to define which is which.

Additionally, with this increase of definition around container magic, I would love if there was a new canon target: container that was smaller than a room (for backpacks, barrels, chests, etc) for +1 mag. Seems like a meaningful change to enable a lot of things people want to do with magic.

Tracing a circle around a consenting or mindless individual is typically as easy as touching it. Type 1 R: Touch T: Circle thus becomes a goto replacement for R: Touch T: Individual in many spells, as it does not increase their magnitude, but is far more versatile.

This way type 1 R: Touch T: Circle will also improve over many type 1 R: Touch T: Room, type 1 R: Touch T: Structure and type 1 R: Touch T: Boundary: the trade-off gets strictly casting time vs. magnitude.

Type 1 T: Circle becomes the goto Target whenever casting time and required presence of the caster at the target are not an issue:

  • preparatory group buffs and protection spells,
  • transport spells - now also out of the circle and far away,
  • transforming or disguising spells,
  • etc.

To keep the many R: Touch T: Individual spells spread over the books unchanged, but still somewhat logical, I would suggest to have the new type 1 T: Circle a recent invention, that has not yet led to the replacement of T-Parameters in spell lab texts and Mastery tractatus.

Does changing T: Individual to type 1 T: Circle result in a similar spell?


I suggested an improvement of terminology already here:

What about adding a level of difficulty to the new T: Circle that cannot be broken? At least for type 1?

Yes, in this case it might make even more sense to call it a T: Circle casting container.

This is a very good point that I need to think about. Quite possibly significant enough to be worth a sacrifice of consistency.

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My only complaint involves the above. Not because I'm not on board with using intuitive definitions of $concept but because this feels like a step away from the newer editions. The first 3 editions of Ars Magica didn't have guidelines. They barely had standardized Ranges and Durations (well, they did, but there were a lot of exceptions). Target parameters didn't exist. All spell levels were determined in the troupe, by intuition and estimation.

Then we entered the age of the internet. We were able to discuss what sort of level a specific spell should be. We discovered that the troupe next town over had different ideas about what 'seemed about right'.
And we standardized. Because that's what you do. Guidelines were formalized and published. Parameters (R/D/T) were formalized and standardized. There was a false start (cough4theditioncough), but we got the Size "pseudo-parameter", which helped.
But now we're going back to intuitive definitions? Is that what we want?
I mean, don't get me wrong, I could go back to the 2nd edition without shedding many tears, but the 5th edition does have some merits :wink:

... and yes, I'm blowing this somewhat out of proportions and probably misrepresenting history a bit. I'm really just trying to explain why these 'intuitive definitions' worry me I guess.

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Let's not. Please.
The ways in which this would be broken is already giving me a headache.

Well, the actual history is roughly that I decided I wanted more detailed guidelines in ArM4, and wrote them, and basically bulldozed Jeff Tidball into including them (a lot of ArM4 worked like that).

For some things, yes, it is. The persistence of an object over time is a notoriously difficult philosophical problem (the ship of Theseus). Whether one thing is inside another can be precisely defined in the real world, but in the game, even if you say "a circle defines a cone from the centre of the earth to the lunar sphere", the answer to the question "is that demon inside the circle?" still depends on the intuitive judgement of the troupe, because you can't actually measure anything.

I don't think we have any choice other than to rely on intuition for these cases, so it is probably more helpful to be upfront about it.


I wasn't privy to those discussions, I can only describe what it looked like from the (far) outside.

Probably true. Does me concern make sense at all to anyone besides me?


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In my opinion, type 1 Circle spells should definitely be "invulnerable" to circle erasure, as you proposed. I see OneShot's concerns, but I think that "invulnerability"'s advantages significantly outweigh the disadvantages.

First of all, it's not just consistency that's at stake. If erasure of the Circle can dispel a type I effect possibly far off, you can act on the Circle to produce long-distance effects on the target in all sorts of strange and very "unmythic" ways - essentially, you have a one-use "off switch" that you can use at an arbitrary distance and without Arcane Connections to communicate information, activate magics (by turning off the metamagic suspending them) etc.

Second, making type I Circle spells vulnerable to circle erasure, rather than encouraging T:Ind and T:group versions of spells where T:Circle might be a cheap replacement, would in my experience encourage "unmythic" behaviours: e.g. casters who remove and safely store away the surface on which the Circle is traced (after a long negotiation with the troupe about the lengths to which they should go to avoid disturbing the circle).

Third, making type I Circle spells vulnerable to circle erasure does nothing for what I think is the most common type of T:Circle "abuse": D:Mom Rituals (e.g. to heal, or to improve characteristics), and in general D:Mom effects (e.g. instantaneous transportation or dispelling).

More in general, I do not think "erasure invulnerable" T:Circle would supplant T:Ind in so many situations.
As OneShot noted, for T:Circle with type I effects to potentially supplant T:Ind, a fairly specific set of circumstances is required: a) multiple targets, and b) consenting (or mindless) targets, and c) R: Touch, and d) D: longer than Mom, and e) the caster having some time even if not a lot. And even then, in most such situations T:Ind is just as effective, and more flexible. One can cast it much more quickly and robustly on a single target in a pinch, while it does not take that much longer to cast it repeatedly a few times so as to affect a whole small group if there's a little time. T:Ind can also be cast through a Wizard's Tunnel (not just a R:Arc version, but also e.g. at R:Sight one); can be cast incospicuously if necessary; and a T:Ind formulaic spell can be designed for a specific individual (e.g. a favourite shield grog) so as not to warp him.

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To be honest, I'd just prefer that there were no 'Type I Circles'.

By comparison, I expect T: Circle-T1 to essentially supplant T: Individual for non-hostile spells in general, much the way I've already seen that trend for non-hostile D: Momentary spells.
Healing boosters in my troupe already tend to be T: Circle, even though people could just cast them while not stressed. Yes, Tunnel spells still require T: Individual. But if you already know the effect, why not just cast it on the grog and keep the circle intact?

Why is this "Unmythic"? Stories are full of wizards and sorcerers with weird bits and pieces that they really don't want disturbed. To quote Archimedes: "Noli turbare circulos meos!"
Surely, that has to be more mythic than dispel magic Unravelling the Form of (Form)?

Maybe take a look at the Vitkir for an entire tradition built around such a concept.

See above.
But also, making these circles immovable (as they should be anyway) would either solve that problem, or force players to think and come up with creative solutions - something that I would generally encourage. Really, what you're writing there looks to me like arguments that either: 1) There should be NO type 1 circles or 2) such circles should be super erasable.

People started using these for healing, because otherwise healing simply got too expensive to be relevant. And as for group teleportation via Circles, well...

  1. it causes Warping, to at least those participants for whom the spell was not specifically designed.
  2. It keeps the group together. We actually tend to prefer this over simple teleportation that splits the group apart and means players sit around waiting, bored, while someone else is travelling.

So, I've been re-reading @ezzelino's post above a few more time. And discussed it a little bit with my SO - who also plays Ars Magica.

We seem to agree that Type I Circles are silly and a bad idea. No surprise there I suppose.

Then I realized that I agree with a lot of the arguments put forth by @ezzelino in the post above, but to me, they are arguments in favour of breakable circles, not against them. Creating vulnerabilities like that seems cool.
In fact, ezze's arguments moved me towards an acceptance of type 1 Circles, assuming that:

  • Breaking them will also destroy the spells they 'support'
  • Anyone able to sense/detect magic should be able to trace the effects of the spell back to the circle, as they are connected by a strand of magic.

I'm still against type I circles though.

PS: Most of what @ezzelino states he wants from "Indestructible Type I Circles", he can get from T: Room. Don't be silly, put in the extra work for those 2 extra magnitudes. It'll be good for you.


This is not about the wizard wanting a circle undisturbed. It's about allowing stuff to be activated at a distance by breaking local circles. Let's look at just one example. Imagine a wizard wants to arm a grog with magical explosives for a mission that will take a few days, without spending any vis, or any significant time. He can then bake a batch of circular cookies. Then he places a raisin on top of each cookie, and he casts a highly destructive effect on each raisin, suspending it with a D:Moon, T:Circle (type I) ReVi spell traced on the outer rim of the cookie.

The destructive effect is then released whenever the ReVi spell expires, i.e. after T:Moon or when the Circle is destroyed, whichever comes sooner. The grog can then place the raisin at the desired spot without breaking the ReVi spell (it's of type I, so the raisin can leave the cookie); lay low in ambush some distance away; and, when a victim arrives, bite the cookie, which breaks the ReVi spell (it's vulnerable to Circle erasure) and detonates the bomb.

Can this fail in many ways? Sure. I mean, whenever I try to store cookies for travel they always find a way to crumble. But my goal was to show the unmythic, "technomagical" uses that erasure-vulnerable type I Circles lead to. Fine if one is playing The Runed Age, less so for Ars Magica, in my opinion. Can immovable circles solve this issue? Partially. But immovable circles preclude lots of other very reasonable uses of Circles, e.g. tracing them on the deck of a ship.

Firstly, would that sort of thing solve a lot of problems in your sagas? Because in most sagas that I've played in, that sounds more like a way to make new problems.

You will also note that, despite your excellent arguments in favour of destructible Type I circles, I'm still not convinced they are a good idea.

Besides, you can do all of that what you just mentioned, using T: Room, no?

I may not have been clear: I find the situation described above "mythically inappropriate".
Since erasure-vulnearble type I circles actively lead to that situation (i.e. make it sensible for PCs and NPCs, to set it up), erasure-vulnerable type I circles are, from my point of view, highly undesirable.

I do not really see how. Perhaps you are willing to elaborate?

How would you, or more importantly, the grog carrying them, would keep the cookies from fragmenting in transit, thereby activating the spell?

Alas, as I said, I tried many ways to keep cookies from crumbling in my travels, and always failed.
But there are many circular objects that are not easy to break accidentally (particularly if stored individually in steel boxes), but are easy to break with a bite or some other quick, decisive action. Unfortunately, they are not nearly as tasty as cookies.

I must admit, I was mainly referring to the raisins-thing.
I've just re-read your post, and appear to have mis-read it in the first place. You're right, you don't actually even need the T: Room for this. You're not suspending the spell, you're putting it in a container, as defined in the Box on ReVi, ArM5, p. 161. What you describe is a Watching Ward.

Or a Charged Item, if you prefer to use your Lab Total over your casting total, and have the time for it.

PS: If you insist on using suppression and not just a variant a variant of Watching Ward, could you provide more detail, because that looks kinda dodgy to me.