How much effort required to customize an existing effect for a new recipient?

How much lab time is required to customize an existing spell or effect, for which you have a lab text, to a new recipient so that they don't suffer warping from its use?

From ArM5, p. 168:
Anyone subjected to a powerful mystical effect gains a Warping Point, unless they themselves were responsible for the effect or it was specifically and carefully designed to work on them. “Powerful effect” is subjective, but any Hermetic spell of sixth magnitude or higher counts. Designing an effect for a particular target requires, in Hermetic terms, that a special version of a Formulaic spell be invented. The spell has its effect on anyone, but only the designated target, and the caster, do not suffer Warping unless the effect is also continuous.

This question is specifically aimed at enchanting items, but the answer would probably apply to learning formulaic spells and rituals as well. Theoretically, a high magnitude spell could use a MuVi effect at the time of casting to avoid the problem - see the related thread here - but that doesn't help with item construction.

The amount of customization in the original spell to work specifically with a single target cannot, I submit, be so intricate that the effect would need to be reinvented entirely. Else the lab text could be reverse engineered to provide a sufficient profile of the author and/or the intended recipient (if any) that you would have a high bonus sympathetic connection, if not an outright fixed arcane connection, similar to a true name. (If a mage can learn a new range, target, or duration from a lab text, without having to devote a single moment of time beyond that already required to invent the spell from the text, they could certainly pull out the unique characteristics of the author and recipient.) And no-one would ever trade a lab text, ever again. So, short of recreating the whole thing, how much lab time is required for the task? House Mercere has to have addressed the matter in the past, if for no other reason than to more efficiently create items using a Leap of Homecoming effect for non-Gifted Redcaps.

Any ideas? I'm tempted to simply handwave away the issue as part of the +3 "restrict the use of a device’s effect to a specific list of people" modifier, assuming the presence of the recipient or an arcane connection lasting for the entire construction effort. Otherwise, my current thinking is to consider it either a 10 day distraction or a require an amount of time equivalent to creating a MuVi 5 effect, whatever is more advantageous for the maga working on the device, and move on. I don't want to ignore the topic entirely --- warping due to high-level effects is a pretty core problem in Ars --- but I don't want to make recreating items from a lab text stupid, either.

As I was considering the matter, it occurred to me that this sounded like the sort of thing that could be addressed by mastery. Would "Flexible Recipients" be gamebreaking as a spell mastery special ability?

You'd still need either an arcane connection or physical contact with the intended target, but it would allow casters who didn't spend a lot of time learning Muto and Vim to avoid warping for their spell recipients on a per spell basis. Maybe restrict the number of targets to your mastery rating? It would certainly be a desirable ability for members of the Cult of Heroes throwing around high-level rituals to increase the attributes of their members. Getting by with a casting tablet would be less attractive if actually learning the spell allowed the possibility to avoid warping the favored sodales. And creating the casting tablet in the first place required a mage who had first mastered the spell - the author would have a real choice between "flexible recipients" and "stalwart casting" as their first special ability learned.

If you made it this far, here is your free pawn of Vim: :chess_pawn: Thank you for your attention.

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I would read "Designing an effect for a particular target requires, in Hermetic terms, that a special version of a Formulaic spell be invented." the following way:

It is not about inventing the spell anew, but the effort is like doing so. To reduce your efforts, you can use an existing lab text or a similar spell known to you.

Generating or keeping a lab text for the adaptation is strictly optional. Making it into an AC you should discuss with your troupe.

Which brings up an interesting concept- having a casting tablet specifically designed for casting on a specific target could prevent warping for very long periods of time with multiple recastings...

As someone who supports more warping in the world, I'm not the best person to ask. I think the strictest reading - it takes a complete rework because targets are designed into the lab text - is reasonably a bit too much. I default towards the next step: if you want to change targets, and have a lab text, reinvent the spell with different harmonic mystical resonances (or whatever) from your lab text. Especially since IIRC they point out that learning spells from teachers or lab texts is essentially reinventing the spell to work for you.
I definitely wouldn't input up a spell mastery that lets you cast high level spells without warping, though I have seen people who've done it. I think it's fine, I just

I have used a spell mastery such that every level of mastery allowed the designation of one extra target to not be warped by the casting...

I'd use the Muto Vim guideline "Superficially change a spell of less than or equal to twice the (level + 1 magnitude) of the Vim spell". You'd need a different version for each different bit of "tuning".

One major downside of enchanting it as an effect is that you can't do it easily in a lesser enchanted device (you could engage a Verditius to reforge it, but that starts becoming a lot of effort).

As someone who dislikes the whole idea of those with the Gifts getting Warping for being under high level magical effects I might not be the best person. So with that said if you really want to reinvent the spell I say make it use the similar effects rule in the spell creation chapter to provide a boost, afterall the mage already knows most of the magic and so it shouldn't take that much to twist it so it applies to a new person. Other than that having a Mastery effect that allows a single spell to be used on multiple people with maybe a magnitude boost or something also wouldn't be amiss.

The one thing I would add is that no matter how many versions a mage might know I think only one should be listed on the character sheet. No need to say a spell and then write out all the names of targets that can be applied to it.

I would consider this : use the lab text and add the magic theory score as a bonus, like when a magus reinvents a (flawed) spell after experimentation. If you feel generous, add the similar spell bonus also. This way, reinventing the spell is easier but not trivial at all.
Or, perhaps "one day per magnitude of the spell". This way, a magus could use a few days each season of lab work to reinvent spells useful for his friends.
Or perhaps, same formula as charged items with a lab text (one per magnitude of lab total), or a variant of this (each copy takes (magnitude of spell) of lab total). This way, the magus must spend a season at least to adapt his spell to other people, but could have several copies in a season. Alternatively, he could reinvent some copies of the spell if he does lab work in the same technique and form combination.


  1. reinvent spell.
  2. MuVi (someone pointed it) and I believe there is, somewhere, a canon spell which does exactly this. Serf's parma on that.
  3. for item, you are screwed. So don't do it for the grog, but onlyfor yourself or the apprentice etc.