Some 5e Spell Questions

Hi All

Our game has moved along merrily for a while and now the players are starting to get rather adventurous with spell casting and I am struggling to find rules that relate to what they attempt at times, some common items are below.

  1. The most common thing is the changing of a known spell on the fly by some degree, such as from Vision to Touch, technically making it a lower magnitude spell, but as per the RAW (as I understand it), making it spontaneous. There seems to be no rules covering this other than "it is a new spell" ?

  2. Arcane Connections. So a player grabs a chair from a room, granting him a vert short term connection to that room. Now he wants to use that arcane connection to cast spells into that room. My initial thought was "well that spell you want to cast requires sight of the target" however Arcane Connection is a superior degree of range so my initial thought seemed to be incorrect, and therefore with an Arcane Connection you could cast any spell, anywhere that you have an Arcane Connection too. In this case the Mage wants to cast an illusion into the room, spontaneous using an Arcane Connection. While this all seems okay...I fear how this could progress....from illusions to ....pillars of fire....

thoughts appreciated!


For 1. Correct, it is a new spell. the major virtue Flexible Formuliac Magic (FFM) allows one step upwrd or downward throough the spell guidelines. Muto Vim spells allow for modification of another Formuliac spell, the book examples show increasing teh range by one step, so rducing the range by 2 steps is a different spell another caster might be able to spont cast.
It comes back to is it easier to spont cast the roublesome Spell at Touch rather than Sight, or cast it at Sight and MuVi spont a spell to reduce it.

For 2. for a spell to use an Arcane Connection it needs to use the Range: AC (+4 mags) and probably Target: Room (+2 mags). You can't just change a spell on the fly to cast at AC.
So you could cast a spell to scry (inIm) into the room by using the AC. However your target is still the room, and not the inhabitants, which means that any spell must affect all the inhabitants if you use T: Room. So yes, a spell could be spont cast to envelop the room in flame using an AC.

Your charaters could also use Opening the Intagible Tunnel (ReVi gen) to alter a T:Touch spell so it is cast upon the Room at range AC. That spell essentially extends any other spell to range: AC. So overall slightly easier if you have multiple magi who will cooperate.

Regarding MuVi metamagic, can you change a spell by more than a single magnitude it, i.e. move it from Personal to Voice, or add two magnitude's of Size increase?

As I understand it, you can change it by two magnitudes by using the General guideline for "Totally change a spell ..." on page 159, in "Muto Vim Guidelines". It's mentioned in the last couple of sentences of that guideline.

So while, yes, it’s technically possible for your players to steal a chair from a room and then go outside and cast a spell to fill said room with fire, in practice that spell is far beyond what they’re capable of using Spontaneous Magic.

What they will want to learn are the rules for Ceremonial Casting, which allows them to get a higher total for spontaneous spells by spending a lot more time. In theory they could also use a Wizard’s Communion to reduce the effective level of the spell, but they’ll need a Sun-duration version to use with ceremonial casting and the consequences of botching could be extreme.

As Ironbound tome says a version of opening the intangible tunnel would allow the characters effectively to use any spell that has equal or lower level to the tunnel spell and is range greater than personal as a range AC spell. As rego vim spells, arcane tunnel spells can be placed in enchanted devices so perhaps the PC's could cooperate to create a tool for the covenant to use (although the guidelines for affecting a spell cast by another, which a device would use, are more challenging.)

Adjusting a spell's parameters is not a thing that characters can do without some assistance, such as metamagic or applicable virtues. Spells in Ars Magica are concrete things that act only as described.

Assuming they are planning on filling the room with fire from just outside, wouldn't it be easier to use touch,or voice, or sight range to the outside of the room, and a room target?

I thought that a Touch/Mom/Room spell would affect everyone inside, or would you need to perceive them first with an intellego spell?

The law of Arcane connections tells us that the caster needs to be able to sense the target. If the target is the room then we have examples to show that seeing or touching the exterior of the room is sufficient.

Range is defined as the distance to the nearest part of the target. the same examples (specifically I was thinking of prying eyes) show us that the exterior of a room or structure is sufficent.

I think that Wraithstalker has a point that, in most situations, grabbing chair would not be the most logiczal thing to do.

I don't think a random chair would necessarily be an AC to a given room. Maybe, if it's an important chair which is always in this room. Like a special chair for the head of the household.

That would work, almost. However, not if you're using Creo Ignem, as Creo must always use the targets Individual or Group - see the box on Creo and Targets, atop p. 113 of the core book. :slight_smile:

No, that should work.

Thanks Tellus, I missed that!

So if I wanted to fill a room with say fire, or illusions, I'd need some way of "targeting" the inside of the room right?

But if I wanted to use Muto/Rego/Perdo to make the room cold using Perdo Ignem, or cause confusion using Rego/Perdo Imaginem that would work with a [Touch/Voice]/Duration/Room target?

Also wouldn't a paint chip or a small splinter from the chair, or one chair from an identical set perhaps, work fine for an AC? The link would be to the chair in the room but that work for most purposes right?

That's my reading of it, yet.