Any (Hermetic or Non-Hermetic) Way to Do This?

One of those things in fantasy (games and otherwise) that has always struck me is that there are special, often-legendary weapons that are particularly effective against certain specific kinds of creatures, like "this sword was forged with special magics and is especially effective against fire dragons." In the general majority of fantasy games, the characters are expected to be the types of people who pick up that sword and slay the fire dragons with it, and not being able to make such a thing themselves means more quests, so the rules for making such a weapon (magically, anyway; "special materials" still require quests to find and so are often put in) are omitted. I wouldn't say that's a bad thing; in combat-centered games, making such a weapon yourself without having to quest for the material to make it would do nothing for the game but let players skip quests. However, Ars Magica is not focused in that particular direction; it's not about combat, or even necessarily quests to acquire materials, and being the "fabled crafter of the Awesomely Named Blade of Slaying Fire Dragons" is a much more tenable choice than in most adventuring-based fantasy games.

However, in the books I own (core rulebook, Covenants, HoH:TL, HoH:S, RoP:I, and RoP:D, though I admit I haven't given the HoH books a deep read) I've seen no way to make a weapon or item that works particularly effectively against specific species of creature. This sounds like something somebody with Faerie-based Supernatural Abilities (is there a name for them? We've got Wizards, Infernalists, and Clerics or whatever you feel like calling Divine Ability-users) would have a knack for; given all the legends associated with weapons (well, items and materials in general, and sometimes food, but you get the point) that are especially potent against specific creatures, and the stories that would obviously be born from somebody searching for and wielding such a weapon, creatures of story like the Fae would probably have a monopoly on designing such a thing. Of course, I could be wrong.

So, are there any ways to make weapons that work especially well against a certain kind of creature, more specifically than just by Realm or Form association? As far as I've been able to tell, the closest thing would be an Intellego effect also enchanted into the item to tell when the weapon is being used against a certain type of creature so it can activate other effects that are just generally powerful, but that feels really cheap, not to mention there would be no real reason for a wizard to intentionally enchant a weapon like that. That's part of the reason I'm looking at other things than Hermetic traditions, but, well... You probably noticed I don't own very many of the books, so I don't know what non-Hermetic source to draw from.

Do one of the books I own have what I'm looking for? And if not, what should the next book on my shopping list be? Does the ability to make such a weapon even exist? (Am I just being derpy and missing something right in the core rulebook?)

I can think of a few justifications for doing the intellego linked trigger arrangement

You could find a spirit that hates or hunts the creature type that you're after then enchant an effect that summons it when the creature is present. Then the spirits special anti creature type magics can come into play.

The enchanter of the enchanted device or the original creator of the lab notes that the PC finds had an appropriate magical focus or magical potency, therefore they had an incentive to create creature type specific enchantments.

And yes, faerie magics are strongly dependent upon sympathy traits. If the magician does not have an appropriate trait, it is exceedingly difficult to effect the target. So your guess about faerie being a source of critter specific weapons was dead on.

Erik is spot on. Another way is the Symbolic/Story Magic in HoH:MC. That kind of magic really would help you get what you'r after.

As far as 'narrowing' it down to a more specific kind of 'target' creature...that sounds like Magical Focuses to me; (and by extention, Poetent Magic from the Mysteries Revised).
It can be done with next to no extra cost (requisites may apply). There just a lot of benefits to do so, outside what has already been mentioned.

Mind you, I haven't checked the Verditius chapter in HoH:MC in a while and we are talking about making magic items...but nothing leaps to mind.

I'll second the above. Grab yourself a copy of that third Houses of Hermes; Symbolic Magic is exactly what you're looking for. It's a Merinita thing, allowing you to work Faerie charms into your magic effects (such as enchanted item effects) and boosts them, but in exchange they only affect the thing associated with the Sympathy Trait you used to work the charm. So you could do exactly what you're saying, making weapons that are (in terms of magic) mediocre in general but extremely effective against specific types of creatures. And, if your magus has a reason to want to hunt those creatures, it makes sense for him to use this method; unlike the method with adding an Intellego effect to activate other powers, which is basically just the magus limiting themselves, Symbolic Magic gives you more power in exchange for only affecting targets within the charm's scope, and doesn't require you to put in strange extra effects to boot so you'll probably save some vis-space.

There isn't really much for non-Hermetics to do here, honestly, since (hilariously enough) most non-Hermetic traditions entirely lack a way to enchant magical devices (though some can engage in enchantment in other ways). Notable exceptions include Learned Magicians, whose main shtick is charged items, and Folk Witches, who don't really even enchant devices so much as they use fetishes to activate powers that they generally couldn't activate without them anyway. Kind of regrettable that most traditions can't truly enchant items, actually... Most just cast spells on items and call them enchanted.

So, yeah. Play a Magus of Merinita and get Initiated into Symbolic Magic if you want to pull this off. (Though the activation has to be tied to the target specifically, as well, so... Hope your SG doesn't think "strike a fire dragon" would require an Intellego effect?)

I think you're alluding to something similar already, and agreed it's somewhat pointless, but you can make a sword that's normally effective against fire-dragons, and useless (beyond being a standard, possible magic-resisted, sword) against everything else. For example, you build a Perdo Animal effect into it which only affects fire-dragons - this shouldn't require any special Intellego requisites.

Play a Verditius and join the Confraternity of Roland, the greatest mage-smiths of swords in The Order. Using the Items of Quality minor virtue from HOH:MC you can create a dagger with a red corral handle that gives the user a +10 against all demons, or a foil with an emerald hilt that grants +7 against serpents. The minor magical focus in swords can be used to affect the blade itself, which means you could use Muto(Te)(Aq) to make the metal a poison that is extra deadly to the species of its intended target, or use Mu(Te)(An) to let the sword function like a hornet's stinger against certain foes. If your target suffers from a malediction, such as "burned by holly boughs" or "paralyzed by the touch of an unbaptized child," the blade could trigger those effects with a Mu(Te)(He) or Mu(Te)(Co) respectively. Note that when you are giving a metal blade extra qualities, and are constrained by two forms, the minor focus really helps to bring your weaker form up to snuff.

From a character perspective, you could choose the flaw "Tormented by Magical Entity" in order to set up a large number of run ins with the same antagonist, and the reason it is worthwhile to forge a special weapon that keeps your tormentor at bay.

This sounds like you need a cult of craftsmen who bring out the shape and material bonuses.

Pretty sure there's a verditius mystery that does that.

Then you need to find the shape and material bonuses appropriate to harming, say, dragons.

Items of Quality is that Verditius Mystery, yeah. On the other hand, I don't think there ARE shape and material bonuses for harming anything as specific as dragons. Shape and Material Bonuses are designed with plausibly boosting item enchanting lab totals in mind, with their Items of Quality application being secondary. About the most specific "harm" you'll find are sword, which harms all people and animals, and red coral, which is a general "versus" demons (and I assume demons is everything with an Infernal Might score). Those are... extremely broad categories.

At which point you'll just have to go into Vulgar Alchemy and invent some yourself.

Or find some that other people invented, that never got spread around the order, because they were too limited.

Against the dark didn't bring upon this idea with the Vampire Hunters Hedge powers?

Which gives you the perfect excuse to go find the bones of a dead dragon. As a SG I'd just tell the players that dragon bones have a shape/material bonus similar to human bone, but towards dragons.

This gives a nice quest to find a dead dragon and scavenge some bone to work into a weapon. Give it to a Verditius to work into a sword and have him use verditius magic, elder runes and items of quality to make a horrifically deadly weapon. Now the enchanter has a reason to limited a PeAn effect only to dragons, he now gets the shape/material bonus to effects that specifically target dragons.

Assuming a great sword, made of steel inlaid with dragon bone, with excellent quality (+3 att and def), +5 to att vs dragons from item of quality, with a PeAn effect to deliver a medium wound upon striking the target (the enchantment only works on dragons so no intellego is required, its not a general medium wound spell) with an obscene penetration.

There is your dragon slaying sword. And as a bonus, the Verditius might be more than happy to make it. Who wouldn't want to be the famed forger of the legendary blade that slew the mighty fire drake of the alps. What fame, what prestige, what bragging rights.

Spells to kill are abundant, but the challenge is more in the Penetration - if we stick to Hermetic Arts.
So maybe there is Minor breakthrough (unless it already exists but is a well-kept secret), which will allow to craft item with unique Penetration properties: instead of getting +2/+1 of spell effect, you get +1 per Sympathy and Penetration links you can have: a gout of its burning saliva, the horoscope of its birth, a scale, a shell from the egg it hatched, some soil from the cave he sleeps in and so on.
By including all this arcane connection and sympathetic connection, the magus get a Penetration of +x/+1 level. Then, it could be possible to have +50 or more Penetration bonus, without turning the weapon into a God-slaying McGuffin, since it will be limited to a single target.

Maybe it is only hedge traditions that have to limit their enchantments thusly.

Learned Magicians, for example. Of course, they cannot create permanent magic items. But I can imagine a variant tradition that, say, cannot do any charms but can create wondrous items.

Gruagrachan also benefit from limiting targets. (They don't enchant either, but...)

No offense to them, as they're all special in their own way, but really, aside from Learned Magicians there really aren't any Hedge Traditions (exempting Vitkir, as they're Gifted-only and nearly on par with Rival Magic traditions, so I don't consider them Hedgies despite their book location) with the inherent power to have anything "legendary" attributed to their name. Even ignoring that most can't make items on their own (because some can, and for others there is Craft Magic, though it wouldn't really give very powerful items to a stronger tradition either) most traditions would just be too weak to make those items that become legendary for knights using them to slay bunches of dragons and stuff.

Of course, that's what Hermetic magic is for. And thanks to Symbolic Magic, I figure any creature that has distinctive racial features could have an item tailored towards them that would have enough additional power behind it to make such limitations worth it. Slightly annoying that it's limited to Merinita magi, but it's the only method I know of based on the books I own to do this in a way that makes sense in-universe without relying on house-rules.

Sort of. The Hunter's Art of Slay allows a Fector to make a weapon against a specific foe. He must have the right Foe Art, and that weapon will only ever work against the individual creature for which it is designed. If successfully deployed (must touch opponent and Penetrate), it inflicts an Incapacitating Wound. Each Slaying weapon is a one-shot device similar to a charged item.

Mark

Thanks Mark by the explanation!