We Need To Talk About Magic Resistance

[scc]

I've been reading through some of the books lately and I've noticed that Magic Resistance behaves very strangely at times.

First up is Simple Illusion, which can be dispelled by someone disbelieving it, which is rather weird as it's basically a Hologram, why would disbelief dispel it? While Magic Resistance isn't mentioned I'm fairly sure that it does actually give someone a bonus to disbelieve the illusion.

Next is Death Vision, which shows someone a vision of their possible demise, this should clearly be Resisted as it's mind effecting, yet it isn't. Also why is this a Necromancy spell and not a Knowledge spell? The only way this makes sense is if death is exclusively the realm of Necromancy, which would mean that you can't use Knowledge spells to divine any information about someone's death.

Third is the Eye of Death, which has Magic Resistance 10 likes to kill mages and it's write-up says that Missile Spells don't work against it, which is rather strange as Missile Spells don't have resistance rolls. Also unless I'm mistaken if you hit this thing you automatically hit it in the eye, which both blinds it and gives you a x4 damage multiplier.

Finally there's the Manaplasm, which has Immunity to Magic, I get what this is intended to do, protect it from magical attacks, but mechanically it doesn't seem to work, Missile Spells will still effect it like the Eye of Death above, as will many other spells, presumably it's supposed to be protected from them, but most magic works indirectly in GURPS and you can't just say that your immune to that sort of thing because it causes other problems, how does it protect you from an arrow or bolt hurled by magic but not one shot by a bow or crossbow?

[Anaraxes]

Sounds more like questions about certain spells in Magic than about Magic Resistance.

Missile spells don't work against Eyes of Death because their description says so. MR or whether or not Missile spells are resisted has nothing to do with it. It's just a feature to make them more menacing to mages. Maybe it's just an inherent Missile Shield. Maybe it's something else. You don't to like them or use them in your game, or modify them to suit yourself. But it's just a monster, doing what monsters do. They don't always have to follow exactly the same rules as everyone else.

Similarly, Death Vision doesn't have a resistance roll because it doesn't have that notation in the spell description. Those are listed spell-by-spell, not derived from some fundamental principle like "all spells that are mind-affecting have resistance rolls". (Notice there's no mention of when to assign resistance rolls in the "Inventing New Spells" section.) You might think it's OP because the other basic stuns give resistance rolls; that's a question of fairness, not a rule. So, want Death Vision to have a resistance roll? Give it one. Don't like the college it's in? Change it to suit yourself.

[Kromm]

Originally Posted by Anaraxes

Missile spells don't work against Eyes of Death because their description says so.

In fact, nothing in their description says anything about Missile spells. The description says these things:

Hovering silently in the dark, they'll use their death rays to kill the opponents most dangerous to them – ranged attackers, like mages and missile weapon users – while remaining at or near maximum range.

Which is to say they'll stay 20 yards away shooting rays at people who might shoot back.

An eye can retreat upward for +4 (not just +3) to Dodge, and/or use Aerobatics for an Acrobatic Dodge (+2); see p. B398. The result is a Dodge of 14 with Aerobatics, 16 with a retreat, or 18 with both! [...] Finally, the eye's Magic Resistance 10 means that spells are even less likely to work than missile weapons.

Which is to say they'll dodge just about anything, and are likely to resist spells that can't be dodged.

None of that mentions Missile spells at all.

[Kromm]

Originally Posted by scc

Finally there's the Manaplasm, which has Immunity to Magic, I get what this is intended to do, protect it from magical attacks, but mechanically it doesn't seem to work, Missile Spells will still effect it like the Eye of Death above, as will many other spells, presumably it's supposed to be protected from them, but most magic works indirectly in GURPS and you can't just say that your immune to that sort of thing because it causes other problems, how does it protect you from an arrow or bolt hurled by magic but not one shot by a bow or crossbow?

It's literal immunity to magic. Magic can't hurt it. That means spells can't be cast on it, Missile spells won't do anything to it, elixirs can't harm it, etc. It isn't immune to rocks, arrows, and so on, so if you shoot stuff at it, that will work however the impulse is given to the projectile. Of course, Diffuse means that mostly won't do a lot . . .

[malloyd]

Originally Posted by Kromm

It's literal immunity to magic. Magic can't hurt it. That means spells can't be cast on it, Missile spells won't do anything to it, elixirs can't harm it, etc. It isn't immune to rocks, arrows, and so on, so if you shoot stuff at it, that will work however the impulse is given to the projectile. Of course, Diffuse means that mostly won't do a lot . . .

The missile spells are the ambiguous bit - especially given the ancient Roleplayer ruling that missile spells *do* continue into and across No Mana Zones, and it's difficult to be more immune to something than it doesn't *exist* in your vicinity.

[Anaraxes]

Originally Posted by Kromm

In fact, nothing in their description says anything about Missile spells.

Thanks for the correction. I just took scc's description at face value, rather than look them up.

(Huh. Turns out I do have DF Monsters 1, after all. Who knew? :))

[Kromm]

Originally Posted by malloyd

The missile spells are the ambiguous bit - especially given the ancient Roleplayer ruling that missile spells *do* continue into and across No Mana Zones, and it's difficult to be more immune to something than it doesn't *exist* in your vicinity.

The DFRPG – which is the only place where the manaplasm exists – isn't subject to ancient Roleplayer rulings. It uses its own definition of Immunity: "Monster cannot be affected at all by the indicated threat regardless of cause or means of delivery." This isn't considered part of the Resistant spectrum of traits in that game, but a special monster ability. In that specific context, it would be pretty strange for Missile spells to somehow not count as "magic."

What causes ambiguity here are (1) porting old GURPS rulings into the DFRPG, and (2) not closely reading the actual words.

[evileeyore]

Originally Posted by scc

First up is Simple Illusion, which can be dispelled by someone disbelieving it, which is rather weird as it's basically a Hologram, why would disbelief dispel it?

Because it isn't a 'hologram' it's an adjusted perception of reality. By disbelieving you no longer allow the mage to adjust your perception of reality.

[Anthony]

Originally Posted by scc

First up is Simple Illusion, which can be dispelled by someone disbelieving it, which is rather weird as it's basically a Hologram, why would disbelief dispel it?

Genre convention that predates GURPS Magic. It's not really clear what illusions are supposed to be in GURPS Magic, a hologram would be a Light and Darkness spell.

[David Johnston2]

Originally Posted by scc

I've been reading through some of the books lately and I've noticed that Magic Resistance behaves very strangely at times.

First up is Simple Illusion, which can be dispelled by someone disbelieving it, which is rather weird as it's basically a Hologram, why would disbelief dispel it? While Magic Resistance isn't mentioned I'm fairly sure that it does actually give someone a bonus to disbelieve the illusion.

Well no. It isn't. Illusion and Creation is it's own college. Simple Illusion is a base spell with no prerequisites except slightly above average intelligence. What that means is Simple Illusion isn't made out of anything except magic and imagination. If someone else refuses to imagine it, it doesn't have enough substance to stay.

Next is Death Vision, which shows someone a vision of their possible demise, this should clearly be Resisted as it's mind effecting, yet it isn't. Also why is this a Necromancy spell and not a Knowledge spell? The only way this makes sense is if death is exclusively the realm of Necromancy, which would mean that you can't use Knowledge spells to divine any information about someone's death.

It's a Necromancy spell because it's once again a base spell and it's only prerequisite for death related spells. And it doesn't have a resistance roll because it isn't an attack. People may be mentally stunned by it but that's because the information it gives them is shocking. What it should do is cause a Fright Check, but it predates Fright Checks. In my update notes I fix that. However, one of the nice things about Magic Resistance is that it gives you a resistance roll against spells that have no resistance roll. As well as being one of the worst things.

Third is the Eye of Death, which has Magic Resistance 10 likes to kill mages and it's write-up says that Missile Spells don't work against it,

You may want to give that a reread.

Finally there's the Manaplasm, which has Immunity to Magic,

No idea what that is.