If a magus wanted to make a superior or excellent quality item, from scratch, using magic, such as Creo magic, is this possible?
I'd imagine that at the very least a finesse roll would be required. But how hard should it be?
City and guilds give the craft levels of Superior items as 12 and Excellent as 15, but these aren't craft ROLLS. They are levels to be beaten by a workshop total. Covenants states that craft magic can accomplish what a craft skill can at +3 on the roll. Could an excellent quality sword therefore be conjured with creo magic and a finesse roll of 18+. Could a sword be forged from steel using rego terram craft magic with a finesse roll of 18+. Could the magus add on points to this roll for quality materials as a craftsman can to his workshop total?
I agree that's what the rules say, not that it's the best choice or even consistent with the setting.
After all, how does one create a majestic tower with Conjuring the Mystic Tower? Isn't that how they're described in Guardians of the Forest? When it comes down to it, if you use Vis to create something it should be pretty awesome, because you're spending resources (time and vis, time to invent the spell, and vis for the ritual), which could be used for different things. Creo crafting should always have a lower ease factor for obtaining these remarkable things, relatively easily, but should be incapable of creating a Wondrous Item.
Rego Crafting ease factors should be harder than Creo, because it doesn't require the input of any resources, except for the underlying raw materials.
As written Conjuring the Mystic tower doesn't replicate standard architectural methods, it simply conjures a really large rock in the shape of a tower. It won't look normal, it is not normal. If you wanted to conjure a regular looking tower made of thousands of carved blocks of stone you would have to use a lot more finesse. The craft rules for finesse only apply when you are trying to replicate the mundane way of doing things through magic. Setting the mundane methods completely aside means you can also set aside the finesse requirements.
So if you simply want to conjure a sword with a razor sharp blade that shows no hammer marks and has clearly never been worked by human hands, skip the finesse roll and maybe add 1 magnitude to the base 5 for unusual properties (exceptionally sharp). Of course it will have to be a ritual if permanent...
Using creo to create artificial items, still need a finesse roll. The RAW that covers this, in I believe, HoH:Societates, states that the ease factors for creo and rego crafting are the same. It doesn't matter whether or not it's possible to create the item with the methods of man (although one could say that it balloons the ease factor to infinity), it's still an artificial item, and it still requires a finesse roll, as specified under the Creo description of the main Ars Magica text.
Some crafting does require a full season equivalent. If your sword, for example, was a shortsword, eight could be crafted in a single season, or nearly three per month. Therefore rego or creo crafting a shortsword would only be at the +3 for magic, +3 for monthly equivalent, for a target number of 18 for superior or 21 for excellent.
If your sword was a longsword, only two can be made in a season, needing the +6 for seasonal equivalent, thus requiring a target roll of 21 for superior and 24 for excellent.
The chart on page 61 of HoH:Societates indicates that the +3 adjustment for magic is already included. So the EFs are 15 for superior, 18 for excellent when making short swords. Long swords would be 18 and 21, respectively. Rereading that chart, it now says that the Finesse rolls for Creo are unnecessary, unless desiring something better than an EF of 9. Which is why I love Ars Magica, contradictions and inconsistencies all over the place.
That's just the rule that you always get something workable out of Creo. It's there because otherwise Creo becomes nearly impossible to use for many standard applications. You want to heal someone? Do you know where all the blood vessels go? Do your ritual and spend the Vis. Now roll Finesse vs 18. Sorry, you lost all the Vis and your buddy is still in pain after that 1.5-hour ritual. There are plenty of other cases like this. So automatic basic functionality is available for Creo, just nothing beyond that without the Finesse roll.
Arts and crafts are especially difficult with Hermetic Magic. If this was a design choice, it was probably made to support the idea that magi need grogs and companions for this kind of thing.
I don't agree about the resources being the issue, but agree with the major issue: Conjuring the Mystic Tower, eh? RAW, the magus has created a massive tower, kind of perfect (because, you know, Creo), but it will have no artistic merit whatsoever and people will not be impressed. There isn't even a Finesse roll.
Stuff I've mentioned before: I don't like the Finesse rules. These rules interact poorly with "add a magnitude for increased complexity and fancy effect." Finesse rolls slow down the game unnecessarily. Having a general rule "Creo spells can achieve a default total of 9+Per+Finesse+(3 * extra magnitudes), and other spells can achieve a default total of 6+Per+Finesse+(3 * extra magnitudes)" would save time and clarify what a spell can do.
Are you opening a canonical pit underneath someone? Your target gets to dodge vs 6+Per+Finesse. No die roll; bad enough we already have one roll to cast the spell and a second to determine damage, which is at least one roll too many.
Why does Conjuring the Mystic Tower need magnitudes for "fancy effect" and how many magnitudes? Just determine the total of what is needed and add magnitudes accordingly. This total is based only on the crafting/artistic total needed.
I think that adding magnitudes for "how long does it take mundane people to do it" is not appropriate. The amount of material worked and the effect worked upon that material are already covered by the spell and RTD guidelines. Paying twice is meh. (Now, an alternate tradition of magic in which difficulty is based on playing with the length of time something takes to do is another story.)
Magic should be awesome; magi stumbling around with the (imo opinion, very unfortunate) rules in Covenants that makes milking a cow a dubious endeavor is not awesome. Magi don't milk cows because they have better things to do and to think about, not because they can't, in the same way that Donald and Melodia Trump don't clean their own toilets.
As for wondrous items, I also agree: There are already rules for creating wondrous items, and Verditius magi are particularly good at this.
So, can it be botched? If it can be botched, you still have the same possibility. If it can't be botched, then...what's the point. I say that somewhat seriously... Does making it Creo make it a non-botching stress roll (this is where I'd go, because of the spending of resources thing)...
I like this no botch idea. With Ken's formula for simplifying Finesse it gets the spells to the place where they are worth developing, reflect the investment, and can also create beautiful results if the caster cares.