Glyph of Warding 3.5: How Many Ways Can You Fool It?

[Duke of Urrel]

The following sentence from the description of the Glyph of Warding spell presents interpretive difficulties for me:

"Mislead, polymorph, and nondetection (and similar magical effects) can fool a glyph, though nonmagical disguises and the like can’t."

Which magical effects, exactly, are "similar" to the spells mentioned?

Should these magical effects include only spells that are (1) of the Figment or Glamor subschool (similar to the Mislead spell), (2) of the Polymorph subschool (similar to the Polymorph spell), and (3) of the Abjuration school (similar to Nondetection); that have similar effects (respectively: (1) visual decoy; (2) changed type, subtype, or kind; and (3) blocked aura detection); and that are also of equal or higher spell level?

Or should these "similar" magical effects also include spells that are of lower spell level, for example: (1) Mirror Image or Minor Image; (2) Alter Self; and (3) Undetectable Alignment?

And by the way, how does a Glyph of Warding respond to the Mislead spell and the Nondetection spell? Is it automatically fooled, or does it make a Will save against the former and a caster level check against the latter?

[Edit: Come to think of it, I'm a little confused about how the Mislead spell works against a Glyph of Warding, since the latter, according to its description, is not fooled by invisibility. Maybe we have to suppose that not every kind of invisibility is equal to every other. For example, as I concluded in another thread, with the advice of the Playground, the Sequester spell produces invisibility that resists detection by the True Seeing spell, but not by a Gem of Seeing or a Robe of Eyes. So maybe the quality of invisibility created by the Mislead spell is superior to that of other invisibility spells, enabling the invisible subject to touch an object or open a container protected by a Glyph of Warding without triggering it. On the other hand, maybe the only kind of Glyph you can fool with the Mislead spell is a trespass-triggered one, using your illusory double to trigger the Glyph while you yourself stand a safe distance away. But can an insubstantial figment, the equivalent of what you could create with the Major Image spell, actually trigger a magical trap that responds to touch or manipulation? What do you think about this?]

I want to get some opinions other than my own before I make house rules to answer these questions, which I believe have no definite answers within the Rules As Written. I always appreciate the help of the Playground in matters like this.

I you're interested, I'll explain why I think the house rules I make for the Glyph of Warding spell have consequences for the similar ones that I will make for the various Symbol spells.

[Segev]

I'd say that the glyph is not fooled by visual deception, but is fooled by actually altering the physical or metaphysical properties of the prospective triggerer. Mislead, for example, specifically causes you to "detect" to magical tests-of-various-properties as if you were the target of the Mislead spell. So the Glyph tries to sense "are you my target?" and gets back "no, that is a copper coin."

Similarly, polymorph or Alter Self or anything else that changed your form would fool it, but an illusion or invisibility would not, because it's using "magical sensor" rather than vision or sound or the like to sense you. It's using something along the lines of Detect Evil - which just asks "are you evil?" - rather than something along the lines of an actual sense.

Nondetection and Sequester and other effects which hide you from scrying and other "detect blah" effects work because they hide you from the capability of something to ask, "do you have XYZ property?"

[Duke of Urrel]

I'd say that the glyph is not fooled by visual deception, but is fooled by actually altering the physical or metaphysical properties of the prospective triggerer. Mislead, for example, specifically causes you to "detect" to magical tests-of-various-properties as if you were the target of the Mislead spell. So the Glyph tries to sense "are you my target?" and gets back "no, that is a copper coin."

Similarly, polymorph or Alter Self or anything else that changed your form would fool it, but an illusion or invisibility would not, because it's using "magical sensor" rather than vision or sound or the like to sense you. It's using something along the lines of Detect Evil - which just asks "are you evil?" - rather than something along the lines of an actual sense.

I appreciate this response, Segev, for several reasons. One reason is that the first paragraph expresses exactly what I used to believe about the Glyph of Warding – and I wonder how many others believed the same thing. But what you described in your first paragraph fits another spell altogether: the Misdirection spell.

I originally assumed that in the description of the Glyph of Warding spell, the rule writers must have made a mistake when they mentioned the Mislead spell. I thought they must have meant the Misdirection (http://www.d20srd.org/srd/spells/misdirection.htm) spell – because it makes perfect sense, doesn't it? I mean, part of what a Glyph of Warding does is detect an intruder's alignment, and like anybody else, I imagined that it did this by means of a kind of aura detection. The Misdirection spell disguises your alignment aura, so it makes sense that this spell would be able to fool a Glyph.

On the other hand, how the heck is the Mislead (http://www.d20srd.org/srd/spells/mislead.htm) spell supposed to fool a Glyph? That spell just turns you invisible – which poses no problem for a Glyph at all. The Mislead spell also creates an illusory double – a figment – and this may possibly be able to fool a Glyph, but figments are insubstantial, so they can't trigger a Glyph by touching a warded object, and certainly not by trying to open something up. If a figment tries to approach a warded doorway, I suppose it can trigger a Glyph that "sees" it approaching, but in this case, shouldn't the Glyph get a Will save to disbelieve the illusion?

I was so confident that the rule writers must have meant the Misdirection spell rather than the Mislead spell that I actually looked for a correction in the Errata, but sadly, there was none. Both my Player's Handbook and the SRD state that it's the Mislead spell that definitely fools a Glyph of Warding, not (necessarily) the Misdirection spell.


Nondetection and Sequester and other effects which hide you from scrying and other "detect blah" effects work because they hide you from the capability of something to ask, "do you have XYZ property?"

I agree with you that a Glyph of Warding must have some kind of magical sense, not exactly sight, but something that detects exactly what the spell's description says it detects. I am starting to think that the three examples given in the spell's description indicate three things that the Glyph can sense about an intruder. But since these senses are not like a creature's senses, they may have unusual strengths or unusual weaknesses.

1. If we assume that a Glyph's power is spell-level based, we may deduce that a Glyph may be defeated by Nondetection, but may still defeat Misdirection and the Undetectable Alignment spell.

2. On the other hand, if we assume that a Glyph works by aura detection, just like a spellcaster who uses a "Detect" spell, we may conclude that both of these lower-level spells work against a Glyph, just as they would work against a spellaster.

I'm still wondering which of these is the better assumption.

Thanks for responding, Segev. I was starting to wonder whether nobody else in the Playground was interested in my questions but me.

[Fax Celestis]

The examples provided all have their own spoofing mechanisms:

Mislead creates a double of you and makes you invisible. There are two spoofing mechanisms here: illusory doubles spoof the glyph, as does being invisible.

Polymorph changes your physiology. The spoofing mechanism here is that the glyph checks for a specific anatomy, doesn't find it, and fails.

Nondetection renders you unscannable by magic. The spoofing mechanism here is that the glyph checks for a target, doesn't find one, and fails.

We can determine the following: the glyph must be able to see you, must be able to physically recognize you, and must be able to detect you. Note that 'seeing' and 'detecting' are two different things.

If the glyph scans your area and does not see you, recognize you, or detect you, it fails.

[Duke of Urrel]

The examples provided all have their own spoofing mechanisms:

Mislead creates a double of you and makes you invisible. There are two spoofing mechanisms here: illusory doubles spoof the glyph, as does being invisible.

Polymorph changes your physiology. The spoofing mechanism here is that the glyph checks for a specific anatomy, doesn't find it, and fails.

Nondetection renders you unscannable by magic. The spoofing mechanism here is that the glyph checks for a target, doesn't find one, and fails.

We can determine the following: the glyph must be able to see you, must be able to physically recognize you, and must be able to detect you. Note that 'seeing' and 'detecting' are two different things.

If the glyph scans your area and does not see you, recognize you, or detect you, it fails.

I believe our thoughts are converging, Fax Celestis, at least to some extent. Here's what I'm thinking now:

1. The Mislead spell can fool a Glyph because, as you say, a Glyph can see. But I think it works only when your illusory double approaches a warded doorway. Glyphs are not foolproof, but neither is any spell you use to fool a Glyph. I don't believe a figment can trigger a Glyph by touching or trying to open a warded object, and I don't believe you can sneak past a Glyph merely because the Mislead spell makes you invisible, because I don't want to assume a "higher order" of invisibility unless I have no alternative.

2. The Polymorph spell can fool a Glyph because a Glyph can be set "according to physical characteristics (such as height or weight) or creature type, subtype, or kind." (Re-reading the words "height or weight" makes me wonder again how a Glyph is supposed to be fooled by the Mislead spell, which merely makes you invisible and creates a weightless illusory double.) The Polymorph spell can actually change your creature type, subtype, or kind. The trick is knowing what type, subtype, or kind of creature a Glyph identifies as an intruder. (Of course, you can't know this about a Glyph unless you use the Analyze Dweomer spell or maybe the Find the Path spell.) It may be possible to fool a Glyph using the Alter Self spell, if changing your "kind" (that is, your species, I presume) is all you need to do. If changing your kind is not enough, then the Alter Self spell won't work, and if a Glyph is set to be triggered by your alignment, not even the Shapechange spell will work.

3. This brings us to the Nondetection spell. This spell can fool a Glyph of Warding, but I still want to know whether the Glyph gets a caster level check. If we assume that a Glyph works by ordinary aura detection, then the Undetectable Alignment spell and the Misdirection spell should work as well, though I still want to know whether a Glyph gets a Will save against the Misdirection. If we assume that a Glyph works by some magical insight stronger than ordinary aura detection, then maybe Nondetection is the weakest spell that can still fool it. Maybe the only other options are spells like Antimagic Field and Mind Blank.

On the other hand, maybe there's no need to toughen up a Glyph of Warding like this. After all, a Glyph can be set to be triggered by the lack of an alignment just as easily as by the presence of one, can't it? For example, if you're Good and a Glyph is set to blast any intruder who isn't Evil, no kind of alignment shielding can save you. The only thing that would work would be to use the Misdirection spell to make your alignment aura resemble that of an Unholy magic item somewhere nearby. For this, of course, you'd need specific knowledge of how the Glyph was triggered.

[Fax Celestis]

Correct on all counts.

Personally, I would look at the trap creation rules in Dungeonscape and how they detect things. A glyph of warding, using those rules, looks like it detects via detect alignment and alarm, and possibly see invisibility and detect magic spells.

[TuggyNE]

2. The Polymorph spell can fool a Glyph because a Glyph can be set "according to physical characteristics (such as height or weight) or creature type, subtype, or kind." (Re-reading the words "height or weight" makes me wonder again how a Glyph is supposed to be fooled by the Mislead spell, which merely makes you invisible and creates a weightless illusory double.)

I suspect glyph of warding was written from a heavily anthropomorphic perspective; a human can look at another human and estimate their weight from visual cues, so the glyph is written to assume the same thing, just magically extended to be more precise and more race-flexible. Kind of stupid, but it is internally consistent.

Edit: put another way, it's English major home automation. :smallsigh:

[Duke of Urrel]

Correct on all counts.

Personally, I would look at the trap creation rules in Dungeonscape and how they detect things. A glyph of warding, using those rules, looks like it detects via detect alignment and alarm, and possibly see invisibility and detect magic spells.

Thanks for mentioning Dungeonscape, one of many supplements I had never heard of before. I have now located the book in digital form online. I am pleased to see that Rich Burlew was involved in writing it! I will definitely read it.


I suspect glyph of warding was written from a heavily anthropomorphic perspective; a human can look at another human and estimate their weight from visual cues, so the glyph is written to assume the same thing, just magically extended to be more precise and more race-flexible. Kind of stupid, but it is internally consistent.

Edit: put another way, it's English major home automation. :smallsigh:

What you say makes good sense. When a Glyph is set to detect a creature's weight, we shouldn't imagine that this is something like Tremorsense – as I confess I have been tempted to do. This "weight" is just part of a creature's observable physical characteristics. Although the word "observable" doesn't appear in the description of the Glyph of Warding spell, it does appear in the description of the Symbol of Death spell, and I believe the word is implied in both places. If a Glyph of Warding can be deceived by the Mislead spell, whose figment has the same quality as one created by the Major Image spell, then I think we can deduce that "observation" here includes everything one can see, hear, or smell about a creature, or feel in the form of radiating heat or cold.

All human language is anthropomorphic, TuggyNE, so I am able to forgive rule writers who anthropomorphize magical traps. But trying to arrive at the right human perspective is sometimes like trying to discover, as a blind man, with the help of four other blind men, what an elephant looks like – to use an old allegory.

As I have mentioned before in this thread, the way I interpret the Glyph of Warding's description has consequences for the way I will interpret the description of the Symbol of Death spell, which applies to all the other Symbol spells. In particular, it has consequences for the following passage: "Special conditions for triggering a symbol of death can be based on a creature’s name, identity, or alignment, but otherwise must be based on observable actions or qualities. Intangibles such as level, class, Hit Dice, and hit points don’t qualify."

I have puzzled long and hard over what is meant by the word "identity" in that passage, but I think the description of the Glyph of Warding, and how I choose to interpret it, is the key to the right meaning. The Glyph of Warding can detect three things: (1) observable physical characteristics (so that it is deceivable by high-quality illusions, but somehow not by mere invisibility); (2) creature type, subtype, or kind; and (3) alignment auras. I think it makes sense to assume that "identity" in the Symbol of Death spell's description means a composite of items (1) and (2) from the Glyph of Warding spell's description plus possibly the name of a unique individual, provided that the Symbol's creator knows this name.

I notice that the two spells have in common a list of things that they cannot detect: class, Hit Dice, and level. Besides, one should never assume that the concept of "identity" includes everything that is not explicitly excluded in the description of the Symbol of Death. That would make this spell too powerful. There must be a list of everything that "identity" includes, and I believe the Glyph of Warding spell's "anthropomorphizing" description nicely provides two out of three items in that list. After all, how does a human being "identify" someone except by observable physical characteristics? The rest of the things a Symbol can detect (type, subtype, kind, alignment, and name) are detectable because of superhuman magic. So I reason (for the time being) that a Symbol is as deceivable as a Glyph, unless the Symbol's creator knows the targeted creature's name, in which case the Symbol cannot be deceived with respect to this creature.

I could go on speculating on what it really means to identify a creature by name. Does it have to be a True Name? Or, if a Symbol responds merely to a common or given name, might it mistakenly blast a friendly creature whose bad luck was to have the same name as the Symbol's intended victim?

But that would be to derail my own thread. I am grateful for the advice I've received. I think I'm close to figuring out how I want to interpret the description of the Glyph of Warding spell. So unless unexpected controversy arises, I'll soon depart and let this thread die.

One final thing: Yes, I think I'm leaning toward giving Glyphs and other magical traps caster level checks and saving throws to resist all possible kinds of deception.

[TuggyNE]

All human language is anthropomorphic, TuggyNE, so I am able to forgive rule writers who anthropomorphize magical traps. But trying to arrive at the right human perspective is sometimes like trying to discover, as a blind man, with the help of four other blind men, what an elephant looks like – to use an old allegory.

To some extent, sure, but (to take an example from my own field) most computer programmers seem to have no very great difficulty avoiding anthropomorphic language usage for the most part; indeed, usually it's those who know least about computers that most tend to think of them like people. As far as I can tell, the same is generally true for the other sciences and disciplines of engineering. This is because these details matter, and if you can't describe them repeatably and concisely, you can't think about them either.

And, as far as I can tell, the writer(s) of the spell did not in fact think about this issue at all.


I could go on speculating on what it really means to identify a creature by name. Does it have to be a True Name? Or, if a Symbol responds merely to a common or given name, might it mistakenly blast a friendly creature whose bad luck was to have the same name as the Symbol's intended victim?

Neither of those options has entirely good results, but since truenaming did not exist when the spells were written, I'm fairly sure it's the latter. "What's a naming collision?" :smalltongue:

Modifying it to give Truename Research something useful to do would probably be superior, especially if you make the subsystem a bit more practical to use.


One final thing: Yes, I think I'm leaning toward giving Glyphs and other magical traps caster level checks and saving throws to resist all possible kinds of deception.

Probably sensible, although figuring out what saving throw bonuses to use might get sticky.