Substitute Finesse checks with complexity modifiers?

Discussion post – Is it reasonable to add magnitudes into Ars Magica spell designs which substitutes Finesse rolls with complexity modifiers?

By RAW no. However as a house-rule it has merit and also is sort of implied by the core rules before all the expansion rules were added. Playing Ars Magica with Core Only is very different from using all the new rules. In fact playing with all the rules would be mind boggling, so a few more choices to suit how players might want to play isn’t breaking. YSMV.

In the base rule book the Finesse skill is not given the same degree of importance to Creo and Rego magic, specifically because new guidelines were introduced in other books. 

As example – A Rego specialist Magus could be designed with a moderate Finesse in core, but would be next to useless in the expanded (now very RAW cannon) Finesse rules; primarily because the target numbers for Rego crafting magic and by extension Creo magic are ridiculously high.

How high? Well a Finesse check in the mid-20s isn’t uncommon, and 30+ is needed for the really cool stuff. In a game with 1d10+skill(1-6)+stat(1-5) that’s punitive.

I previously wrote about using time as a mitigation for Finesse checks for Creo ritual spells, and I think the suggestion makes sense. Essentially it allows a high degree of preparation to mitigate the Finesse roll, as long as the spell also has a complexity modifier built in (just as Conjuring the Mystic Tower has, which was a spell written before the expanded Finesse rules). This allows a way to rationalise the rules where one ritual spell does not require a Finesse roll, but the instant Rego/Crafting spells still do.

So what about expanding that house-rule to allow additional mags to add a bonus to the Finesse check?

Suggested new Guideline:


Caster gains +3 bonus to the Finesse check for each Magnitude added for Finesse Complexity in spell design. This complexity may only be added where the description also produces a higher quality and beauty item, and must produce a more specific result for each step in magnitude.

I’m a supporter of this principal too, as I see spell complexity as a representation of increasing detail mandated in a spell (as if the spell is an architectural design or a script).

I also like the idea that magic can have many ways to do the same thing, and a spell designer could build knowing that their version of a spell is far higher than another wizards, but they get to an almost identical result.

Along with that Finesse check should be a restriction on the purpose of the spell. A Creo spell to create a sword could have a lot of variety in the result. A ritual using this suggestion to create an ornate and wonderfully crafted sword should note what the additional complexity is for.

This ensure that the complexity added for component parts, or high detail is different from the “complexity for Finesse replacement”.

Quoting from and E.g. from the Atlas Forums by Virgileso:

Echo of Durendal

CrTe 40, R: Touch D: Momentary T: Individual

This spell creates an excellent quality steel longsword, granting the wielder a +4 Attack & Defense in combat due to its uncanny craftsmanship.

(Base 5, +1 Touch, +6 complexity)


Designer’s Notes: Rather than requiring a Finesse check against an EF 30 for such a sword, I am instead obliviating the roll altogether and setting the spell’s crafting total to a flat 12+(3*complexity) against an EF as per the Rego Craft Magic guidelines set forth in Covenants.

I don’t think it’s game breaking. My interpretation of the spell above would be that it will create an identical weapon each time it is cast because the design adds 6 magnitudes for the Finesse bonus.

It is a different style of solution to adding time (above), and while it’s plausible that these options might be used in combination a table of players would probably need to pre-select if either option was allowed and carry that forward in their games.

Happy games folks.


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