With Definitive, we've had something of a revision/clarification/expansion of the "Magical Craft" rules (see the eighth page of the PDF of the Chapter 9 draft, numbered p.310) compared to the somewhat-contradictory mess we previously had. I was poking at spell design and then at the Grand Grimoire of Hermetic Spells in light of the new official approach, and had some thoughts about systematization.
These are house rules, of course, but rather than change how Definitive works, they're intended to make it easier to make new and legacy spells consistent with Definitive. (The only change to a spell in Definitive's rulebook itself would be altering Conjuring the Mystic Tower's design section using my proposed "standardized" terminology.)
1. Elaborate design and Creo magical craft
The Creo Animal and Creo Herbam guidelines have modifiers for how much humans have reshaped something from its natural form. Creating a “natural” product is Base 5 or Base 1 (respectively), creating a “treated” product (leather, jointed meat, cloth, cut timber, or a vegetarian meal) is +1 magnitude above the natural, and creating a “processed” version of a treated product (clothes, furniture) is an additional magnitude. Creo Herbam then has wood (and presumably other natural Herbam) in an “unnatural shape” use a guideline two magnitudes higher than the natural product, effectively saying that whether your useful human-imposed shape looks like it was crafted or just grew that way, you pay the same price.
Creo Terram’s guidelines, on the other hand, do not have that. While a bridge of wood will cost you two magnitudes (whether apparently manufactured or grown) over a natural tree, a wall of stone will cost you nothing extra over a boulder. Creo Terram’s guidelines do specify one additional magnitude for “elaborate shape”, and that’s that.
It is true Conjuring the Mystic Tower as published has three magnitudes for “elaborate design”, which in books after the original core produced lots of analogies in other spells for creating artificial things. But Conjuring the Mystic Tower allowed customization when casting, which is called out in the new Magical Craft rules as something (“normally”) requiring additional magnitudes.
Extra magnitudes for elaborateness of an object’s design beyond the established guidelines per se seem to be inconsistent with the newly clarified Magical Craft rules. If casting a spontaneous spell or a spell with room for customization, elaboration is a matter of hitting the Finesse targets. With a fixed effect Formulaic or Ritual spell, elaboration is a result of effort spent working out precisely what the spell is doing in months of inventing the spell. The Storyguide might, if the spell is particularly ambitious, require a successful Finesse roll while inventing the spell; Craft the Mechanism (The Mysteries, 52) is a precedent here.
However, it does seem reasonable that the nature of magic might require a magnitude for something that straddles the line between Individual and Group targets by being a single object with multiple moving parts; see “Moving Parts” in the new standardized difficulty modifiers below.
2. Suggested new standardized spell difficulty modifier terminology for Creo magical craft
Customization: This indicates a Formulaic or Ritual creation spell that allows customization of the object it creates (see the Magical Craft rules in Chapter 9: Spells of the Definitive Edition).
One magnitude of customization is seen in the spell The Riches That are Rightfully Mine(d) (Covenants, 61); two are seen in Conjuring the Mystic Tower. Even more flexibility requires more magnitudes. Remember that customization to the point of allowing the creation of items of notably high quality is at least +3 magnitudes.
Moving Parts: This indicates a single object is made of multiple parts that are supposed to be able to move relative to each other in predictable ways. It is always +1 magnitude. It should not be applied to (for example) cloth, even though cloth is composed of threads that move some relative to each other.
Variety: Creation spells usually create just one specific thing, and if the target is Group, all the created items are identical instances of that thing. For each magnitude spent on variety, the number of different things a Group target creation spell can create is increased by a factor of ten. These things still must match the Form of the spell, and the amount of material created will be governed by the base Individual of the most difficult of the things created. (For example, if a single Creo Terram spell is used to create both brass disks and diamonds, the maximum total volume created will be according to the guidelines for gemstone.)
In the case of a Formulaic or Ritual spell, all of these different things still will be specified in all details at the time of the invention of the spell, unless magnitudes are also spent on allowing customization (see above).
The variety modifier is directly inspired by the commentary in the spells The Creation of Acorns Aplenty and The Creation of a Forest (Transforming Mythic Europe , 62).
3. Notes on some existing Creo spells
(As listed in the Grand Grimoire of Hermetic Spells, with page references for that work.)
Animal
Sturdy Mantle of the Traveler (p.6): Delete everything from “A Finesse roll…” to the beginning of the design notes, since this has been superseded by the new Magical Craft rules. For a version that allows style variations (and things like different sizes for different wearers), change to Level 35 and add “+1 customization” to the design section.
Herbam
The Miniature of Immortality (p.94): Replace “+1 complexity” with “+1 customization”.
The Travelers’ Fortress of Cloth (p.94): Delete the whole “A Finesse roll…” sentence, since this has been superseded by the new Magical Craft rules. There’s no obvious need to customize the tent each time it is cast, instead of producing the same tent each time. But if you do want a customizable tent, add +1 or +2 customization and increase Level to 25 or 30 accordingly.
Conjure the Mighty Barn (p.94): Replace “+2 elaborate design” with “+1 customization, +1 moving parts”. Level is unchanged as a result.
Conjuration of Bread (p.95): Change to Level 20; replace “+5 size” with “+2 size”.
(This spell as written is insane; a base Individual of Herbam is a cubic pace; a Group is the size of ten Individuals, so ten cubic paces; +5 magnitudes of size then produces 1 million cubic paces of bread, or more than 200,000 tons. Either a thousand cubic paces (200 tons) of bread is enough to justify the spell’s +7 to supply rolls in a season, or no amount of bread is enough to justify it.)
Running Repairs (p.95): As written, this spell is now just 1 magnitude less than the reworked Reparation of the Wounded Vessel below , which seems obviously wrong. So, let’s redesign.
It is unclear what guideline is being used as the original’s Base here. But in any case, with Definitive, we now have healing guidelines for plants, and we have a repair-all-damage guideline for crafted Herbam items. We can see that “Heal all Wounds to a plant” is two magnitudes below “Restore a manufactured wooden item that has been damaged to the peak of its capabilities”, which actually matches the general +2 magnitudes to go from creating plants to creating treated and processed plant products like clothes and furniture. Object damage levels seem to me to be most analogous to Light Wounds. This changes the spell to “Base 1”, but we keep the “+2 treated and processed Herbam” from the existing design description. This removes two magnitudes.
While the Terram requisite is necessary to cover incidental metal bits of the ship, it does not increase the power of the spell, and “+1 Terram requisite” bit should be deleted from the design section, saving a magnitude.
The spell would thus become Level 15, but a ritual has a minimum level of 20.
Fortress of Oak (p.96): Replace “+3 elaborate” with “+2 customization, +1 moving parts”. Remove the “+1 Terram Requisite” and “+1 Muto Requisite” from the design section. The Muto requisite is at best symbolic based on the initial acorn, and probably should be eliminated as a requisite entirely. As far as the Terram, the spell would not be substantially less powerful absent the earthen floors and hearths, and so does not justify a magnitude. The spell is now Level 30.
Conjuration of the Seaworthy Cog (p.96): First, as the spell by its text creates the same ship every time, under the new Magical Craft rules, there should be no need for the Finesse roll. Any corrections for design defects and wear in the prototype really needed to be incorporated when the spell was invented.
Second. as the base is 3 (either creating treated and processed wood, rather than a natural plant product, or creating wood in an unnatural shape), there should be no additional “+2 treated and processed Herbam”, reducing the spell level by two magnitudes. (Yes, one could argue that a ship is both wood in an unnatural shape, and then it’s also a treated and processed product, but that’s double-counting that would make a finished wooden plank Base 4 instead of Base 2.)
Third, while the Terram requisite allows for bolts, nails, and other fixtures, it does not substantially alter what the spell does or its power; there should be no “+1 Terram Requisite” magnitude increase, reducing the spell level by another magnitude.
Fourth, since the spell doesn’t allow customization, the “+3 intricacy” is a synonym for Conjuring the Mystic Tower's “elaborate design” that isn’t justified. We do have separate moving parts, like rudders and hatches, so we replace it with “+1 moving parts”, another net -2 magnitudes.
That leaves the spell, in the end, at Level 20.
Reparation of the Wounded Vessel (p.96): Suggested rebuild is to replace the design with “(Base 15, +1 Touch, +3 Structure.)” Repairing/replacing the Terram components of the ship is enough to have a requisite, but isn’t additional functionality/power for the spell justifying an additional magnitude. Now Level 35.
Terram
A Network Reminiscent of Rome (p.186): As written, under the new Magical Craft rules it will create a road/road network of the very same design every time.
A System of Narrow Canals (p.186): As written, under the new Magical Craft rules it will create a canal/canal network of the very same design every time.
Canals that Accommodate Seagoing Vessels (p.187): As written, under the new Magical Craft rules it will create a canal/canal network of the very same design every time.
Creation of the Walls of Simple Cottages (p.187): The justification for “+1 complexity” seems odd; since this only raises walls, which are all connected, why would it need to create “multiple objects” in a precise order? However, with all the runners connecting the cottages, it certainly does seem to qualify for the Terram guideline of “+1 elaborate shape”. Note the spell level works out to 15, but the minimum for a ritual is 20.
(Contra the published design note, a Group target would only add one magnitude to start, since it would save a size magnitude.)
Efficient & Permanent Wall of Protecting Stone (p.187): As written, under the new Magical Craft rules it will create a wall of the very same design every time.
Permanent Wall of Protecting Stone (p.187): As written, under the new Magical Craft rules it will create a wall of the very same design every time.
Seal the Breach (p.188): Replace “+1 finesse” with “+1 customization”.
The Thirsty Dagger (p.188): Replace “+2 elaborate design” with “+1 elaborate shape”. Level unchanged because of the minimum for a ritual anyway.
Arms of Neptune (p.189): Change to Level 30; add “+1 variety” to the design section, since the trident and shield are different objects. The specified intricately-wrought nature of the trident and engraved design in the shield is purely cosmetic, so probably doesn’t justify a “+1 elaborate shape”. The Finesse customization with each casting can either be deleted or add a “+1 customization”, but at this point adding another magnitude would seem like piling on.
An Expansive & Permanent Wall of Protecting Stone (p.187): As written, under the new Magical Craft rules it will create a wall of the very same design every time; particularly pertinent here, given the great length.
Creation of a Legion of Appointed Cottages (p.189): Replace “+2 complexity” with the more specific “+1 elaborate shape, +1 moving parts”.
(Note that since the spell is not Group, thanks to the stone runners dodge, there is, in fact, no need for all the cottages created by a single casting to be identical, or to invent a new version with “+1 variety” to vary them; they can be designed to be different when the spell is invented.)
Creation of a Well-Appointed Town (p.189): As with the previous spell, replace “+2 complexity” with the more specific “+1 elaborate shape, +1 moving parts”. Since the spell is not Group, there is no need for all the cottages created by a single casting to be identical.
Silvery Scales of the Knight (p.190): The Finesse roll as written is inconsistent with the new Magical Craft rules. Allowing reasonable customization (like as to size) would seem a good idea, and adds a magnitude (“+1 customization”). Replace “+2 very elaborate shape” with “+1 elaborate shape” and maintain the level. The layers (padding/gambeson) and separate rings of the mail and such do not qualify as true moving parts.
The Wealth of Croesus (p.190): Without any magnitudes for allowing customization (see the very similar The Riches That are Rightfully Mine(d) below), the Finesse roll to customize the design to match coinage should be deleted under the new Magical Craft rules. The caster gets out the same coin design that he put in when inventing the spell.
Note the spell says “13,000 pennies”. Since there are 240 pennies to the pound, 650 Mythic Pounds “should be” 156,000 Mythic Pennies. Presumably the text once said “shillings” (650×20=13,000), someone noticed that silver shilling coins didn’t exist in 1220 AD, and the revision to match that fact was incompletely made.
Conjuring the Mystic Tower (p.190): Replace “+3 elaborate design” with “+1 elaborate shape, +2 customization”.
Craft the Mechanism (p.191): Under the new Magical Craft rules, if you got the design right when you were creating the spell, it shouldn’t require a successful Finesse roll to be functional when you cast it. Delete that bit, and replace the “+2 finesse” with “+1 elaborate shape, +1 moving parts”. It should have been Level 30 in any case, since (going back to The Mysteries) there’s no actual Intellego requisite.
Duplicate the Mechanism (p.191): I assume you’re trying to duplicate a mechanism in your current presence (in which case this is an exception to creating the exact same thing every time rule, but we can treat the Intellego requisite as providing the mechanism for that exception). If you’re trying to duplicate a design you have in your lab when you’re inventing the spell, that seems to be a case of the Craft the Mechanism spell above, using the model (and maybe your Intellego magic to examine in) to make it easier to invent the spell. Replace “+2 finesse” with a “+1 elaborate shape, +1 moving parts” as above.
The Riches That are Rightfully Mine(d) (p.191): Replace “+1 complexity” with “+1 customization”.
Conjuring the House of God (p.192): Replace “+3 elaborate design” with “+1 elaborate shape, +3 customization” (as it allows substantially more customization than Conjuring the Mystic Tower , such as in external dimensions). That makes this a Level 50 spell.
The Laboratory of Bonisagus (p.192): This creates the same elaborate equipment every time, but the pieces of the equipment aren’t all identical to each other. Replace “+5 complexity” with “+1 elaborate shape, +1 moving parts, +2 variety”. The spell becomes Level 40.