Phantom Trap

No matter how long you've been playing this game, no matter how many times you've reread the Player's Handbook, I find there's always some obtuse spell you've never seen before. Case in point: I recently stumbled across a core spell called phantom trap that I swear I've never laid eyes on. Unlike a lot of these obscure and worthless spells that crop up now and then, however... this one I kind of wish I had. It's strange, so strange that I'm having trouble thinking of any real, practical applications for such a spell. That said, it is worth investigating by virtue of how unique it is - and likely more for the DM than any of the players. The text for phantom trap is as follows:

Illusion (Glamer) Level: Sor/Wiz 2 Components: V, S, M Casting Time: 1 standard action Range: Touch Target: Object touched Duration: Permanent (D) Saving Throw: None Spell Resistance: No This spell makes a lock or other small mechanism seem to be trapped to anyone who can detect traps. You place the spell upon any small mechanism or device, such as a lock, hinge, hasp, cork, cap, or ratchet. Any character able to detect traps, or who uses any spell or device enabling trap detection, is 100% certain a real trap exists. Of course, the effect is illusory and nothing happens if the trap is “sprung”; its primary purpose is to frighten away thieves or make them waste precious time. If another phantom trap is active within 50 feet when the spell is cast, the casting fails. Material Component A piece of iron pyrite touched to the object to be trapped while the object is sprinkled with a special dust requiring 50 gp to prepare.

So the first thing that jumps out at me is that we're dealing with a 2nd level Illusion spell that is Permanent. Not Permanent until discharged, just flat-out Permanent. That's pretty unusual, and probably is why the spell calls for an expensive material component. The next thing that stands out is that this spell permits no saving throw and no spell resistance, so it's pretty hard to get around for anyone walking around without true seeing active. Just to reinforce the fact of being unable to save against phantom trap, the text goes out of its way to mention that the spell is 100% effective: "any character able to detect traps, or who uses any spell or device enabling trap detection, is 100% certain a real trap exists." No check, no save, no nothing: it always just works. This gets even weirder when we consider that anyone with Trapfinding doesn't have to actively be looking for traps to see the illusion - apparently all they need do is look at the enspelled item to see the most definite trap they've ever seen in their life.

Isn't that unusual? Note that the text makes no effort to specify what the onlooker thinks such a trap might be, of course. Likewise, no mention is made of whether there is any way to disable the "trap," unless we're meant to infer that it falls under the general Disable Device rules for 'magic traps,' which the spell... kind of is? I mean really it's not a trap, just an illusion that makes someone unshakably think that a trap is present, but if that's the case, then anyone who tries to disable the "trap" will always be convinced they failed to do so. After all, they will still always know with absolute certainty that a trap is definitely there, no save allowed.

Now even if someone decides to open up the enspelled item and seemingly nothing happens, they still think a trap is there. Remember, with "100% certainty." After all, you'll remember I pointed out that the spell doesn't discharge, and thus it's still present, making anyone (with Trapfinding) able to see that it's clearly trapped. The text clarifies that "nothing happens if the trap is 'sprung'," and I feel like an onlooker realizing that the item is in fact not trapped would qualify as something happening. Thus, phantom trap persists.

It goes even deeper. Since there is no "disbelief" clause (and therefore the "you automatically disbelieve your own illusions" rule won't apply, any more than you could see something you cast invisibility on just because you're the caster; both phantom trap and invisibility are [glamer] spells with no saving throw to disbelieve, so presumably they work similarly in this regard) then if the caster of phantom trap possesses Trapfinding or something to the same effect, then even they believe with absolute certainty that there is now a trap on this item. The spell doesn't specify affecting "anyone other than you," it just works on anyone who can detect traps. As a result, this little detail makes phantom trap probably a poor choice for a spellthief or beguiler to pick up.

Another fairly unique feature of phantom trap is that it fails if another iteration of it exists within 50 feet: somewhat logical, but pretty easy to play around. To state what is perhaps the obvious, it is apparently possible to cast the spell on many different objects that are then brought together after the fact. Consider a series of nested chests, each bearing a phantom trap - a rogue picking his way through them would always be convinced that the next one is definitely trapped, no matter how many he goes through. Having said that, knowing that the spell will fail only if it's near another instance of the spell is also usable information. A player could cast the spell as a test to see if anything in the room they're searching already bears a phantom trap. Of course, this wouldn't do much good to anyone capable of finding traps, since they would nonetheless believe with unshakeable certainty that the target is trapped. But hopefully at that point a party member unable to find traps can throw out a detect magic or dispel magic.

Ultimately, that is the spell's biggest weakness: it only works on characters able to find traps. The other is that its effects are only truly as effective as the spell promises if the players are good at NOT metagaming. Assuming everyone is able to give this illusion the reaction it's due, then, what exactly can be done with it? Phantom trap is a very unusual spell that's bound to have a few tricks go with it as a result. 

You could cast phantom trap on an object and then follow it up with animate objects to give you a creature that irrefutably appears trapped. What does this mean? As a DM, what would your players make of this information - a construct that explodes when struck? Better yet, you could polymorph any object someone into an inanimate object, target them with phantom trap and then wait for the polymorph to expire. The result is a person or creature that appears "trapped" to all characters who can find traps, which should... definitely seem weird. Probably the natural assumption would be an explosive construct like above but in a convincing human guise (an assumption that would be potentially reinforced when a foe casts detect magic and picks up on an illusion aura.)

Borrowing the idea of gathering multiple phantom traps together from above, I suppose the premiere use of this odd little spell would be to... maximize sheer player frustration. Imagine a dungeon preceded by a magic trap that casts find traps on anyone who enters. The whole place is a labyrinth full of a mix of real traps and phantom traps, not to mention a sprinkling of Trap Haunts (Dragon Magazine content alert!) A Fiend of Possession could inhabit a phantom traps to even give it a negative effect in bestowing curses upon any who touch it - but remember, no amount of Disable Device can turn this effect off! It's not a trap, it's just a possessed object that looks trapped. Make your players absolutely hate traps, real or otherwise. After all these years of scorching ray, invisibility and alter self, why shouldn't the DM get a level 2 spell to fall in love with? Telling the ghost of Gary Gygax to hold your beer is probably a good way to suddenly stop being the DM, but this whole setup would probably be remarkably effective. At what, I dunno... but effective.