[Christopher R. Rice]

Originally Posted by Icelander

What is the canonical way to enchant a bullet as a charm so that it does extra damage against certain categories of foes?

Add an appropriate Destroy or Create Effect and then add damage; use the rules for Ammunition Charms (GURPS Thaumtology: Ritual Path Magic, p. 27). This is usually a Lesser effect. For example, Lesser Destroy Spirit + Damage, Indirect Burning might be the equivalent of "holy bullets" that burn demons.

(Aside: You can add a Lesser Destroy Spirit effect to simulate a "holy attack" - it doesn't do damage on its own but relies on a target's traits. You can stack this effect with damaging spells.)

Originally Posted by Icelander

I understand this could be done with Bestows a Bonus, but let's assume we want to have the option of higher damage than that open.

You could increase the basic damage of the firearm this way, but adding indirect/external (linked attack) or direct/internal (a follow-up) is possible too. For example, see here.

Originally Posted by Icelander

Is there any way to make the damage either part of basic Dmg of the bullet (and thus adding for the purposes of penetrating DR) or at least Follow-Up?

See above.

Originally Posted by Icelander

And while damage would seem to fit under Destroy Matter for normal targets, Destroy Spirit for ghosts, qlippoths and demons and Destroy Undead for zombies or vampires, could extra damage to "all supernatural targets" be Destroy Magic?

Mmmm. Maybe. If that's how you want to play it. I would probably use Path of Spirit myself - but that's no real matter.

Aside: I personally would call qlippoths something from Path of Nonexistence (GURPS Thaumtology: Ritual Path Magic, p. 37)

Originally Posted by Icelander

Can anyone good with RPM rituals write up a sample Supernatural Bane bullet Charm that does an extra 2d pi (ideally added to the bullet damage for DR purposes, Follow-Up if that's imlossible) to any supernatural target?

Since most things are resistant to piercing - I wouldn't use that. Use crushing or impaling instead. The write up itself is pretty simple (as I showed above).

Originally Posted by Icelander

As a damage bonus with a weapon is a narrow category, there doesn't seem to be any incentive to cast a ritual giving a bullet Charm a bonus to damage only against a specific category of foes, when you can have an unlimited damage bonus against any target for the same energy cost.

This seems to lead to uninteresting results, as I find the idea of Werewolf Bane, Ghostkiller or Supernatural Slayer bullet Charms much more flavourful than Bullets of +2 to Damage. And while I might allow basic enchanted bullets that hit harder, I would like Bane bullets enchanted against specific foes to receive a substantially higher bonus damage for the same energy cost.

Again, you don't need to add damage bonus to increase the damage of a bullet charm. You can add the Damage modifier and do any amount of extra dice.

Originally Posted by Emerald Cat

One rule hack would be to apply an advantage limitation as a discount on the energy cost. Accessibility Limitations or the Limited Defenses modifiers for defensive abilities would be good candidates.

Either set of limitations would give large discounts if the susceptible targets were defined narrowly. This could potentially become game breaking. The main downside for such limited banes is that charm slots would be wasted if used on an invalid target. To fully exploit the discount, the PCs would need to do their research and figure out what they are going up against. In my opinion, this would be very fitting for a monster hunters game.

Players may also try to break the game by claiming discounts on broad categories of targets. GM fiat will be required to establish balanced discounts. But this shouldn't be any more difficult than the GM calls RPM already requires.

Originally Posted by Icelander

I've seen write-ups for Rituals where the limitation rules are used, but I'm not sure what the official rules are for using Limitations as part of the RPM system. I'm very much in favour of it myself, but I want to avoid any pitfalls that playtesting might have revealed.

I wrote this up in Pyramid #3/66 (p. 38) as "Repercussive Rituals."

Originally Posted by Icelander

Should the Elder Sign be a Ritual in RPM terms or merely a symbol that, if properly drawn (with Symbol Drawing or maybe even Occultism with the right familiarity), triggers Dread in the appropriate beings?

I think you could do both - as you note below.

Originally Posted by Icelander

Of course, there's nothing preventing it from being both. Characters without Ritual Magery or even ritual magicians without time to gather energy can make use of the symbol to drivee off creatures with Dread, but when used as part of a Ritual, the Elder Sign reduces energy cost and the effects can be much greater than merely Dread, including banishment or binding, not to mention giving the those warded some much needed protection from terror, madness and the like.

How about something like anyone can draw it, but those with the right ritual can empower it and make it better. Perhaps a magic-based Elder Sign causes a Fright Check or outright damage, while a drawn one just triggers Dread

Originally Posted by Icelander

Has anyone written up Lovecraftian rituals or the protective effects of Elder Signs?

I wrote up Song of Glissande here