Traps with Onset Delays

[Stormborn]

Traps that never miss have onset delay, to make them fairer I suppose. How Exactly do they work?

Take this trap from the SRD:

Dropping Ceiling
CR 9; mechanical; location trigger; repair reset; ceiling moves down (12d6, crush); multiple targets (all targets in a 10-ft.-by-10-ft. room); never miss; onset delay (1 round); Search DC 20; Disable Device DC 16. Market Price: 12,600 gp.

Fairly low Search and DD for 9th level, but lets just say that the Rogue rolls very poorly on his Search or DD. The trap is sprung!

The PCs then have 1 round to get out of the way? Does that mean no one ever gets hit?

I can see the trap being more dangerous if the doors to the room slam shut, but that seems to simply take it from "Never" to "Always." Or would the Rogue then have a chance to redeem himself by either Disable Device on the doors or Open Lock?

I can also see where this trap, set in a larger room, could crush something the PCs are after, or block their means of egress from a larger dungeon so that they are forced to find a different way.

Is the trap, or others with a delay, effective as is? I wanted to use this trap at the antechamber of a tomb my 11th level PCs are going to be entering next session. But other than as a means to keep them out or lock them in (neither of which seems to be a lot of fun) I am begining to wonder if its the way to go.

 

[javcs]

Have the interior door of the antechamber locked - and possibly with a trap on that as well to keep them busy.

Say that the Ceiling trap is triggered when the door unlocks or the trap on the door is disabled - it doesn't start dropping until the next round, however - make it a moderately high Listen Check (DC in the mid-20s) to notice something creaking. Alternatively, you could give them a fairly high Spot or Search check to notice something funny with the walls around where it falls.
Remember, if the trigger is inside the wall or on the other side, no Search Check will find the trigger.

Give them an Obvious Trap(tm) to draw their attention; remember, Searching for traps requires deliberate action and takes time - also, if they don't Search the Room (which, if you give them something to distract them with, is less likely to happen) as a whole, but only say 'I search the door for traps' or some such, specifying an object or area other than the ceiling, they don't find that trap.

Remember, to use Search, they need to be adjacent to the area they're searching - with a high (15ft or more) ceiling they'd need to climb the walls or fly to search it - if you use a magical trigger, such as an Alarm spell or something similar/suitably modified for use in traps, then all you need is a cover for that trigger, such as an Obvious Trap(tm).

An Obvious Trap(tm) doesn't necessarily have to actually have a trigger to set it off - you can fool someone into thinking they've disabled the Obvious Trap(tm) by jamming the apparent mechanisms, instead of disabling the trigger (to the ceiling trap). If they decide to be clever about it, and disable the trigger without setting it off, but leave the Obvious Trap(tm) mechanisms functional, you can say the trigger for the Obvious Trap is on the other side of the door.

If you haven't made your PC's utterly paranoid, then any of these ideas will probably work adequately well for your purposes.

 

[prospero63]

Fairly low Search and DD for 9th level, but lets just say that the Rogue rolls very poorly on his Search or DD. The trap is sprung!

OK, but they don't know that the trap has been sprung.

The PCs then have 1 round to get out of the way? Does that mean no one ever gets hit?

Obviously the situation will ultimately dictate it, but it's certainly possible. Or they stay where they are because nothing happened and the thief tries it again, then whammo.

In reading your post it seems you might have some assumptions that I don't think are correct (you might not, but I'm just putting them out for the sake of discussion).

1) That a thief knows what the trap is. I don't think that is the case. I have seen a lot of folks do it that way, but I'm fairly certain that search and trapfinding simply tell you "yep, it's trapped".
2) It's not until the disable device that the theif can learn what the trap is, how it works, etc. and then only by beating the DC by 10. If he missed the role (thus springing the trap) then he's totally unaware...
3) Search and Disable Device rolls are always rolls that the DM should make. The best players in the world use the information from the rolls, even though they shouldn't. I've seen some that automatically trigger the trap if they fail because "it's the right thing to do, I shouldn't know I didn't disable it" and others that go to the other extreme and try over and over and over again, or do whatever they can to make sure they don't set off the trap they know is still there.

I've always handled the rolls with basic information. You found a trap or you didn't find a trap. With regards to the disable device, "something goes wrong" doesn't always have a noticeable effect. So the response is generally "You think you got it" (which could be wrong based on "something goes wrong"). "You don't think you got it" (which again could be wrong based on "something goes wrong"). And of course "something went wrong" which could be exhibited by the trap going off right that instant, or could appear to be "you don't think you got it" because the trap is delayed and while you sprung it now, it's not going to go off till next round.

Make sense?

 

[irdeggman]

javcs - remember that changing the situation (like having a locked door and/or obvious traps) will add to the EL by making the encounter more difficult.

 

[Stormborn]

Right, if there are locked doors etc it changes the EL, if i had more than one trap finder who could deal with a second locked door or trap that wouldnt be a problem, but I dont so it is.

Prospero's advice is good, but it would largely mean changing how I handle those rolls in mid game. I dont want to do that.


This is what I think I will do: Let the PC search for traps and disable as I have always done. If the PC fails I will just say "nothing seems to happen" - they have run into traps that no longer work before - and then roll Listen checks for them. I dont think the DC will be too high, stone scraping on stone or sand support empting should be in the 15-20 range I think and most of them have poor Listen skills. If they make it the PCs can have a chance to escape, if not we will just hav to see.

 

[prospero63]

Right, if there are locked doors etc it changes the EL, if i had more than one trap finder who could deal with a second locked door or trap that wouldnt be a problem, but I dont so it is.

Prospero's advice is good, but it would largely mean changing how I handle those rolls in mid game. I dont want to do that.


This is what I think I will do: Let the PC search for traps and disable as I have always done. If the PC fails I will just say "nothing seems to happen" - they have run into traps that no longer work before - and then roll Listen checks for them. I dont think the DC will be too high, stone scraping on stone or sand support empting should be in the 15-20 range I think and most of them have poor Listen skills. If they make it the PCs can have a chance to escape, if not we will just hav to see.

Cool. The only thing I would mention is that a delay trap doesn't necessarily imply that something happens during that delay round. I know, evil, but I'm cut from the grimtooth mold so I like some nasty traps from time to time.

Good luck!

 

[irdeggman]

IIRC the Disable Device check is one of those that the DM must make and not the player. That is, it must be "secret".

Search is something different.

 

[prospero63]

IIRC the Disable Device check is one of those that the DM must make and not the player. That is, it must be "secret".

Search is something different.

Yeah, I actually make it a point to keep the skills and various circumstance modifiers of the PC's in a spreadsheet (actually, it's largely their responsibility to update me with relevant info as I have a "the spreadsheet never lies" policy) and handle many of the spot, listen, search and related checks without the players knowing. As I have mentioned, it seems like no matter how good the players are, when you say something like "give me a spot check" it just tips them off that something is going on. IMO it defeats the purpose of things like surprise, etc. In fact, I have even been known to make saving throws on their behalf, again so as to not tip the players as to things that might be going on that they shouldn't know about (and I do take into account that the PC knows when they make a save... but I can handle that privately in IM, again keeping the facade up, or letting the player respond as they desire). In fact, we had a funny thing a session or so back where a player knew that something was illusiory and failed to tell the party. One of the players got a little upset with me that they should have known, blah, blah, blah. I finally broke down and said "you know, your PC has no way of knowing this, but I told so and so and they chose not to tell the rest of you, so go chew on him for a while".

Sorry for the hijack.

 

[irdeggman]

One of the players got a little upset with me that they should have known, blah, blah, blah. I finally broke down and said "you know, your PC has no way of knowing this, but I told so and so and they chose not to tell the rest of you, so go chew on him for a while".

Sorry for the hijack.

LoL

The 2 most "common" problems in our gaming group over the years have been:

Ranger out scouting ahead of the party - decides to single take on the war party he "finds" by himself and not report back.

- oops looks like we need another ranger

The other one - characters on watch don't bother to wake up those sleeping when the "see" something. This happens over and over and over again - I have no idea why people can't realize the main function of the watch is to "wake up" everyone and not try to take things on themselves.

 

[javcs]

So true , Irdeggman, so true. I still haven't decided which one I think is worse.

javcs - remember that changing the situation (like having a locked door and/or obvious traps) will add to the EL by making the encounter more difficult.

True - however, I'm not sure how much the EL would change if you have a decoration in the room that just looks like a trap but isn't one - ie apparent holes in the walls, polearms mounted on the walls (apparently on a pivot) over doorways, illusion of a pit/pit with invisible cover on it(so not a pit at all), etc. I suppose it varies ...
The more complex you make the distractions, definitely the more dangerous it gets.

Stormborn, what kind of characters do you have as your PCs? Also, if they don't make the Listen checks to notice it, but you don't want a TPK, consider allowing someone adjacent to an open doorway a (high)Reflex save to dive through it, landing prone on just the other side of the doorway. High enough where a high-Dex, high-Reflex class would not make it easily.