First Attempt At Inventing A Fifth Ed Spell

Hi everyone! New to the forums and I suspect that this is one of those "plz do my essay" type threads of which people grew tired long ago, but I'm on the lookout for some spell advice.

I've not played AM since 3rd edition and I'm in the process of putting together a campaign. One of the NPCs I'm working on is a Maga Trianoma with an emphasis on diplomacy, and due to the way I'm setting up the game I have a number of characters with different languages and no unifying Latin. So I figured this would be exactly the kind of thing a diplomatic Trianoman would have worked at in the past, and started trying to work out a mass "everyone understands each other for the immediate future" spell.

Best I can manage at the moment from the spell guidelines is a Muto Mentem (Intellego req) spell to grant everyone the same magical sense as Thoughts Within Babble. My understanding is that this means the base effect of TWB is increased by 1 magnitude, and then the spell has to be brought up from 5E's universal base. I went for the lowest things that would let my Trianoman drop that effect on a selected group of people with some preparation.

So, as far as I can tell, that gives me:

Effect Base Level: 10
Range: Personal -> Touch (+1 mag)
Duration: Momentary -> Concentration (+1 mag)
Target: Individual -> Circle (+0 mag)
Sense: None -> Hearing (+3 mag)

That gives me a final effect level of 35, right? Or have I missed something?

Considering that it is a Circle, you might have to bump duration to Circle as well (+1 mag).
It will have the advantage that you magus does not need to keep focus and can actively participate to the discussion.

The main challenge I would see is more practical: convincing magi to enter a circle and watch you cast a spell, which for all intent could be an "enslave" spell (it is after all a MuMe spell, so for non-specialist it might be hard to distinguish).
The second challenge, magus would have to drop their Parma, because I do not think you will get a high enough penetration with such high level spell to affect any magus with a decent Parma.

Also it cannot be cast discretly on the group of persons as the maga has to draw the circle around the people she wants to affect. It will be hard to use with mundanes as they would immediately see magic at work - unless they are aware of who she is and what are her intentions.

Yes and no. It seems you've missed the tricky bit about Target - . When designing a purely sensing spell - like Sense the Nature of Vis - it is usually R:Personal and the Target is the sense the spell uses - you don't need to mix in any Target modifier as well
So it's one or the other. Target should be Hearing, as the original TWB. So don't add anything for Target otherwise. But you didn't, since Circle is +0.

Following the rules on ArM5 page the spell needs to be Muto (Intellego) Mentem. The Range is the range to the recipient. Had it been a T:Group spell you could have gone with R:Personal. So R: Touch sounds right.

Gift of Understanding, Mu(In)Me35
(Base 10, +1 Touch, +1 Conc, +3 Hearing)

page 114. first column.

With T: Circle, it's the range to the circle really.

No! No! Bad! Bad!
Like T: Room, T: Group cannot be R: Personal, because R: Personal makes restrictions on the target.
T: Group must be atleast R: Touch.

We could try:
Gift of Understanding, Mu(In)Me 20
(base 10, +1 Touch, +1 Conc, +0 circle, requisite necessary, so free)
which would allow those within the circle to understand each other, but not necessarily those outside the circle.
I would also strongly recommend going for
Circle of Understanding, Mu(In)Me 25
(base 10, +1 Touch, +2 Ring, +0 circle, requisite necessary, so free)
instead, to take advantage of the circle you'd have to draw anyway.
And forget about passing it off as non-magical

First of all, it should be Base 5, rather than Base 10.

Also, as was pointed out by another poster, the problem is that usually spells granting magical senses only affect an individual at a time. The "Target" is the "Sense" in these cases, so your spell would become R:Per D:Conc T:Hear.

It is possible (see ArM5, p.114) to grant senses to multiple people at once, but this requires Muto Mentem magic with Intellego requisites. However, the rules do not clearly define the final level in this case (if you just assumed it was Mu(In)Me with T:Circle, you'd end up with a spell three magnitudes lower than that to affect a single individual!); personally, but it's just me, I tend to treat the "Sense" as a plain magnitude modifier. So your spell would become Mu(In)Me level 30 (R:Touch, D:Conc, T:Circle).

The level calculation is Base 5 +1 Touch+1 Conc+1 Circle+0, +3Hearing (the last modifier is my interpretation).

ezze is right about the base, ofcourse.

Okay, I stand corrected about R: Personal and T:Group. Even though I found no provisions under the description of Group, I certainly did find it under Personal ("The Target can thus never be larger then Individual). And it seems reasonable that Personal can't be used with Room anyway, since you are rarely a room yourself...

As for the Base I totally did not check that, Base 5 it it.

Designing the spell using Circle and/or Ring does make it significantly different from TWB as written, since this is a T:Hearing sense spell. However these do seem iffy beyond the personal versisons, and the proposed design seems streamlined and effective.

But I still don't see the wish to add +3 mags for Hearing. The spell is either a 'normal' spell using the normal Targets (Ind, Circle, Group etc), or else it is a 'magical sense' spell using the Sense Targets (Vision, TOuch etc.)

I set the base effect level at 10 because of the Muto Mentem guidelines box text, pg 150:

I can definitely see that there are two possible arguments regarding the Sense element. I should really make a decision on an interpretation for that case in case my players want a similar effect later. The suggestion of making it Ring is an excellent one, I'll add that in. I think this Trianoman can just about scrape out a level 40 Mu/In/Me...

I'm currently calling it "Circle of Babel".

The idea was that it was invented to facilitate negotiations between mundanes. I can definitely see it being a problem for Magi, but virtually all Hermetics speak Latin anyway. In the context of my campaign, my players will be starting as potential Apprentices anyway, so the issues of application are mostly moot. (I like the cultural and communication issues their different languages cause, but there needs to be a way to make them all able to understand what is happening IC.)

I could enchant a room, and it would still need R: Touch to use T: Room.

Yes, because T:Room affects things in the room.

However, a R:Personal, T:Individual effect could concievably be enchanted into a room. Say, a Muto Terram effect to cause the roof to turn transparent (potentially, the effect would need size modifiers). But like you say that is not using T:Room.