Seeking Practical Advice on...Symbol Spells

[Nail]

Backing away from the Boolean Logic for a moment:

Symbols are nasty.......but how do they interact with a Rogue's trapfinding ability? I'm not convinced that question has been answered yet.

Let's say a symbol activates if anyone comes within 60 feet. In other words, the triggering mechanism of this trap is 60 ft proximity to the symbol. This triggering mechanism is part of the trap itself. Since it's part of the trap, the rogue can find it.

All traps—mechanical or magic—have the following elements: trigger, reset, Search DC, Disable Device DC, attack bonus (or saving throw or onset delay), damage/effect, and Challenge Rating.

The spells explosive runes, fire trap, glyph of warding, symbol, and teleportation circle create magic traps that a rogue can find by making a successful Search check and then can attempt to disarm by using Disable Device.

Rogues (and only rogues) can use the Search skill to locate traps when the task has a Difficulty Class higher than 20.

Before you jump the gun, consider this: Most traps (magical or mechanical) will have a triggering mechanism, and this may be located far from the "business end" of the trap. (A ballista on the other side of a door is a simple example.) Ruling that a rogue cannot find triggering mechanisms, but must instead must find the "business end" of the trap, would effectively neuter the Trapfinding ability.

Also note: I'm focused here on the Search check, not the Disable Device check.

 

[Shadowdweller]

I don't see why this would be the case. The party *might* (under unusual conditions) be able to spot the symbol more than 60 feet away, and tell that it's "a symbol of some sort." That hardly amounts to bypassing it, or even identifying it. I'd say the necromancer's still getting his money's worth.

One can just as easily bypass the whole "visible outside of 60 feet thing" by placing the Symbol on the far side of an archway with the triggering condition of "whenever someone passes under this archway." The Symbol itself won't be visible UNTIL someone passes through said archway.

Before you jump the gun, consider this: Most traps (magical or mechanical) will have a triggering mechanism, and this may be located far from the "business end" of the trap. (A ballista on the other side of a door is a simple example.) Ruling that a rogue cannot find triggering mechanisms, but must instead must find the "business end" of the trap, would effectively neuter the Trapfinding ability.

Ah, that's an excellent way of solving the balance issue of the unfindable trap! Seems like it could add some excellent drama to the game as well:

DM (to the Rogue): "Carefully scrutinizing the stone floor, you can make out what looks like faint convection blurring down the passage ahead." Then party knows there's something nasty ahead but not necessarily what it is or how to deal with it.

 

[Infiniti2000]

Let's say a symbol activates if anyone comes within 60 feet. In other words, the triggering mechanism of this trap is 60 ft proximity to the symbol. This triggering mechanism is part of the trap itself. Since it's part of the trap, the rogue can find it.

You took a leap of logic in your 3rd sentence. Why can't the triggering mechanism be the symbol itself? Just because it can, say, sense a victim 60ft away, that doesn't make the triggering mechanism 60ft away. The entire trap, including the triggering mechanism, can easily be viewed as being wholly contained in the area required for drawing the symbol. As an more illustrative example to my viewpoint, consider a fireball trap that activates when you step on a pressure plate. The fireball is set off right at the plate. Does the rogue find the trap 20ft away from the pressure plate or at the pressure plate? Now, consider if the fireball instead goes off 100ft away towards the north. Can the rogue find the trap in a 20ft radius 100ft to the north of the plate plus the area at the plate? How about the area in between?

Before you jump the gun, consider this: Most traps (magical or mechanical) will have a triggering mechanism, and this may be located far from the "business end" of the trap. (A ballista on the other side of a door is a simple example.) Ruling that a rogue cannot find triggering mechanisms, but must instead must find the "business end" of the trap, would effectively neuter the Trapfinding ability.

I agree, but defining the triggering mechanism and even sometimes the business end are not always so easy. In the case of the symbol of death, I don't agree that the triggering mechanism is not the symbol itself. After all, you have to see the symbol (in the OP's implementation). Closing your eyes and walking past the symbol is a perfectly acceptable counter (and could very well be the result of the 'disable device' check).

 

[Patryn of Elvenshae]

The key at this point is to phrase the Boolean logic correctly. One way is to negate the original equations such as !(X AND Y) = true, or !X = true AND !Y = true. Unlike originally, these statements are no longer strictly equal. The second one with two separate statements clearly shows that both must be false (i.e. the symbol is neither visible nor legible beyond 60ft).

Except, as you just pointed out, the two statements are not equal - you've violated the laws of boolean math. Drawing any conclusions from this is incorrect.

Note that (!X and !Y) is one case that evaluates to the same as !(X and Y) - it is not, however, the only one. You cannot make the statement that it is not only a subset of the answers, it is the set of all answers with the data we have.

Now, we have made one inference not present in the "source data" - that if something is not visible, it is not legible. In other words, (!X and Y) (invisble and legible) does not appear in the "real world" set of possibilities.

That still leaves us with (!X and !Y) (invisible, illegible) and (X and !Y) (visible, but illegible) as two potential ways to come up with the opposite answer to (X and Y).

Barring further information, you cannot claim that one or the other is the only way - they both are.

The problem with that is that Patryn (and others) choose Y to be the 'culprit' rather arbitrarily and not both. Why is not merely not legible when not visible and not legible is also possible?

Does the above change your mind?

 

[Infiniti2000]

... That still leaves us with (!X and !Y) (invisible, illegible) and (X and !Y) (visible, but illegible) as two potential ways to come up with the opposite answer to (X and Y).

Barring further information, you cannot claim that one or the other is the only way - they both are.

...

Does the above change your mind?

I don't think I changed my mind, but I agree with the above. I think you merely made it sound about a bajillion times clearer than I could. I was under the impression that you (and the others) were saying that one way (visible, illegible) was THE way (meaning only way).

However, I still choose (invisible, illegible) as the way spell works (and I'll be sure to note it in my list of houserules) on the grounds that I think it's more appropriate for the spell level, but YM clearly Vs.

 

[Patryn of Elvenshae]

I was under the impression that you (and the others) were saying that one way (visible, illegible) was THE way (meaning only way).

Nah - just pointing out that a DM could rule either way and be consistent consistent with the rules.

I, personally, go with visible but illegible at greater than 60 feet, rather than invisible beyond 60 feet, because that seems to make more sense to me.

 

[Saeviomagy]

Frankly, I think that to make the game anything approximating fair, you have to allow detection of a trap at any point that it interacts with.

ie - you can find it at the trigger point, the mechanism itself, the activation point, and any point that is hit by the trap.

"You pull out your bug-in-a-jar-on-a-pole, and probe forward with it. Suddenly the bug dies in a gruesome fashion. It would appear you've found some death magic trap".

Same goes for "the symbol above the other side of a door" trap.

You have to assume that the rogue has either an impressive array of tools and tricks, or that his trapfinding is quasi-magical.

Unless you do that, you should advise your players that trapfinding is likely to be useless in your campaign to prevent them from wasting their time on it.

 

[Shadowdweller]

Frankly, I think that to make the game anything approximating fair, you have to allow detection of a trap at any point that it interacts with.

ie - you can find it at the trigger point, the mechanism itself, the activation point, and any point that is hit by the trap.

Same goes for "the symbol above the other side of a door" trap.

You have to assume that the rogue has either an impressive array of tools and tricks, or that his trapfinding is quasi-magical.

Unless you do that, you should advise your players that trapfinding is likely to be useless in your campaign to prevent them from wasting their time on it.

While I largely agree about allowing rogues to detect traps, the take 20 and autoscour the surface leaves a lot to be desired in terms of playability. What I've taken to doing as a DM (House Rule) is giving only SOME of the trap information when a search is successful. For instance, rather than simply stating "You find a dart trap in front of you," I might say "You discover a number of odd holes in the walls before you." When a rogue attempts to Disable a trap, I ask for a method (making allowances for the extent of IC knowledge of course) of attempting it. Sometimes this results in a penalty or bonus to the check. Some methods simply don't work. Sometimes the rogue/party have to experiment a little with the trap before they can determine a means of disarming/avoiding it.

What this means is that traps become puzzles rather than simply statistics. And the rogue remains a valuable party member.

"

You pull out your bug-in-a-jar-on-a-pole, and probe forward with it. Suddenly the bug dies in a gruesome fashion. It would appear you've found some death magic trap".

Given the nature of how activated Symbols work, you really wouldn't want to pull that particular one...

 

[Nail]

You took a leap of logic in your 3rd sentence. Why can't the triggering mechanism be the symbol itself?

It (the triggering mechanism) is part of the trap. The definition of traps tells us as much.

Since it is part of the trap, the rogue's trapfinding ability can find it.

 

[Infiniti2000]

It (the triggering mechanism) is part of the trap. The definition of traps tells us as much.

Since it is part of the trap, the rogue's trapfinding ability can find it.

I agree, but the triggering mechanism is the symbol. Being in close proximity to the symbol does not mean that the triggering mechanism is "being 60ft away from the triggering mechanism." Your previous post tried to show rules-based reasons for allowing this and I disagree with the attempt (though not necessarily the spirit of the attempt). In other words, your quotes with the yellowed text do not prove that a rogue should be able to find a symbol of death from 60ft away.