How does D&D 3.5e handle the case where the means of bypassing or disabling a trap is located somewhere other than the trapped door/lock/...? For instance, take an electricity-based trap (such as an electrified door) where the electricity source is located somewhere else -- you can't simply cut the wires, because that'd trigger an uncontained arc and quite likely shock you in the process (considering that insulated cutting tools aren't a thing in your average Rogue's toolbox), but if there's a switch somewhere else that turns off the electricity to the trap, bypassing/disabling it is simply a matter of finding and flipping said switch. However, neither the PHB nor the DMG provides rules for Disable Device when the means is remote from the trap.

Am I correct in that there's a tacit assumption in most D&D play that all Disable Device rolls are made at the site of the trap? Or can the location where a given trap's Disable Device roll must be made be somewhere besides where the trap is actually found at?

  • \$\begingroup\$ Note that while a rogue's toolkit probably doesn't include insulated tools, it may well include leather gloves. More specifically, they're included in a number of the free starting outfits popular with rogues. \$\endgroup\$
    – GMJoe
    Feb 16, 2015 at 23:20
  • 1
    \$\begingroup\$ Leather gloves by themselves are a bad idea when working on live parts. To quote the link: "FAST FACT: Do not use leather protectors alone for protection against electric shock. Serious injury or death could result. Always use proper rubber insulating gloves." \$\endgroup\$
    – Shalvenay
    Feb 16, 2015 at 23:38

5 Answers 5


Consider, rather than flat out not allowing Disable Device to work at the trap site, to have it work both at the trap and the breaker box. But make the breaker box DC considerably lower. (Say, by 5-10 points of so)

It allows for more flexibility, isn't as more annoying for the Rogue anda actually grants some additional choices into the encounter: risk the much harder DC to break the trap here, or risk exposing yourself to danger to get to the breaker box, where shutting down the trap is easier.


You are correct that the rules assume that Disable Device checks are typically done at the site of the trap. D&D traps pretty much always assume that traps are things that can be disabled at the trap. That said, I don't think there'd be any problems with just saying that you need to use disable device on a breaker box nearby or something. It wouldn't meaningfully alter the CR of the trap, unless the thing you needed to disable was far away.

That said, I feel like this is going to be very frustrating for the rogue. One of the big reasons to play a rogue is to be the one who disarms traps and does other skillmonkey things. Making a trap that a rogue is not allowed to bypass with Disable Device seems a bit cruel. They might not have insulated cutting tools, but an arrow shot from a foot away can still probably cut through a wire. The point of the vagueness of Disable Device and the trap disarming mechanics is that characters can do things that are ingenious and unexpected without the players needing to be experts in disarming traps as well. This feels like taking away a trick from the rogue for no real benefit.

  • \$\begingroup\$ Is there a reason the rogue must use Disable Device to bypass/disable the trap? I'm trying to determine if the problem at hand is having a trap a rogue can't disable to begin with, or if the problem is that the rogue's Disable Device doesn't work on this trap, even though the dungeon provides him with several other options. \$\endgroup\$
    – Shalvenay
    Feb 19, 2015 at 1:17
  • \$\begingroup\$ I don't know that I can usefully answer that comment any more that I have already in my answer. In 3.5, the only skill used for explicitly disabling traps is Disable Device. If you make a trap that, for some weird reason, cannot be disabled with Disable Device, then the rogue who invested a bunch of points in Disable Device is going to feel like those points have been wasted. \$\endgroup\$
    – DuckTapeAl
    Feb 19, 2015 at 1:55

Yes, there's a tacit assumption in most D&D play that all Disable Device rolls are made at the site of the trap.

A good point about disabling traps to understand is that the terms "disable" & "bypass" do not necessarily mean "turning off." While it can mean this it can also mean to make the trap not function as designed. So while I may not be able to "cut" the wires, I can short circuit the path with a bit of metal (coin, knife etc) which diverts the electricity from the door I need to get through.

Main difference between this and using a "circuit box" is that, unless the circuit box is complex any character should be able to flip a switch & turn off the electricity but only the rogue (similar class) will be able to "disable" the trap. That said, ofcourse you can make a complex circuit box that only a rogue can disable. if it is this complex it should send a loud & clear (read:painful) message when a non-rogue attempts to mess with the box.


Ranged Legerdemain
An arcane trickster can perform one of the following class skills at a range of 30 feet: Disable Device, Open Lock, or Sleight of Hand. Working at a distance increases the normal skill check DC by 5, and an arcane trickster cannot take 10 on this check. Any object to be manipulated must weigh 5 pounds or less. (DMG 178)

The restriction that you cannot use Disable Device at a distance isn't explicitly stated but clearly is implied by this prestige class ability.

The rules for Disable Device also state

Other Ways to Beat a Trap

It’s possible to ruin many traps without making a Disable Device check.

Ranged Attack Traps
Once a trap’s location is known, the obvious way to ruin it is to smash the mechanism—assuming the mechanism can be accessed. Failing that, it’s possible to plug up the holes from which the projectiles emerge. Doing this prevents the trap from firing unless its ammunition does enough damage to break through the plugs.

Melee Attack Traps
These devices can be thwarted by smashing the mechanism or blocking the weapons, as noted above. Alternatively, if a character studies the trap as it triggers, he might be able to time his dodges just right to avoid damage. A character who is doing nothing but studying a trap when it first goes off gains a +4 dodge bonus against its attacks if it is triggered again within the next minute.

Disabling a pit trap generally ruins only the trapdoor, making it an uncovered pit. Filling in the pit or building a makeshift bridge across it is an application of manual labor, not the Disable Device skill. Characters could neutralize any spikes at the bottom of a pit by attacking them—they break just as daggers do.

Magic Traps
Dispel magic helps here. Someone who succeeds on a caster level check against the level of the trap’s creator suppresses the trap for 1d4 rounds. This works only with a targeted dispel magic, not the area version. (PH 73)

I think there's quite a bit of insinuation here that the DM should not treat a trap as an atomic unit, rather as many parts, any one of which may (or may not) effectively disable the trap if 'disabled' or smashed.

The point is; don't think of the trap as one unit, rather think about how is it triggered? what happens when it's activated? what are the mechanisms? Is it one direction? Is it the same from multiple directions? If there is an owner or inhabitants, how do they get by it? Is the bypass one switch, or multiple? How does it reset? What part or parts are detectable? Do you need multiple search DCs? Do parts of it "hide in plain sight"? Is any part magical? If so, make sure and look up detect magic and each spell involved so you can have those spellcraft DCs, schools and strengths written down in your notes.

Good luck.

  • \$\begingroup\$ Problem is, the traps in question fall into none of the categories listed in the second quote, and smashing parts is useless in this case -- you'll just get zapped for your trouble. I'm personally inclined to Rule 0 that Disable Device can work at a distance if the trap is "strung out" as in the case I gave -- I appear to have found a case that 3.5e's designers never stopped to consider. \$\endgroup\$
    – Shalvenay
    Feb 17, 2015 at 23:15
  • \$\begingroup\$ Further feedback from a test playthrough with a medium level hedge wizard -- much of these traps are "hidden in plain sight", and there are no arcane parts, so no spellcraft DCs apply; however, spells such as Mage Hand and Mending can be used to deconstruct or bypass these traps. There are bypass switches in some parts of the dungeon, but I am expanding on them further, and may rearrange the doors altogether due to the foibles of random dungeon generation... (Also -- there are no actual triggers for these traps) \$\endgroup\$
    – Shalvenay
    Feb 18, 2015 at 23:22

An alternative in this case would be to allow the rogue to make the Disable Device check, and if that is passed, tell him how to disable the trap. Say he realises that cutting the wires would trigger the trap anyway (or has a crazy high DC at least), but "he notices that the wires lead into the wall to the east". Or something.

Like a Knowledge check, with a higher roll getting more information about the trap. If you plan to have multiple ways to disable the trap, then he might uncover some, all, or none of these methods depending on his role.

Then, depending on what he learned and how he chooses to proceed he may need to roll another disable device check to actually enact the method (say he follows the wires to the room down the east corridor and discovers the power source, he could make a check to disable this).

This still provides some benefit for the rogue, as his skill doesn't become totally useless (a sucess tells him how to disable it, and maybe gives a hint as to what to do), while allowing you to make traps that are spread across more than one location.

  • \$\begingroup\$ Not a bad thought; however, the traps in question can be disabled in several ways even when limiting the party to dungeon manipulation -- and the DC varies depending on how you're going about it! (There are very strong simulationist reasons why these traps do not have a constant DC across disable techniques which aren't going to go away just to fit a notion of how 3.5 should work.) \$\endgroup\$
    – Shalvenay
    Feb 19, 2015 at 1:02
  • \$\begingroup\$ I wasn't suggesting the DC needs to be the same for everything. You could say that the higher his initial disable device check, the more information he gets from the trap about how to disable it. Like, say he rolls badly, he has no idea how to disable it, slightly better he only finds out the "high DC"/inconvenient way to disable it, and the higher his total the more info he gets, or the more options he uncovers etc. Almost like a Knowledge(Traps) check. \$\endgroup\$ Feb 19, 2015 at 2:54
  • \$\begingroup\$ I see...so he makes one roll and the results of the roll determine how he disables it... \$\endgroup\$
    – Shalvenay
    Feb 19, 2015 at 12:39
  • \$\begingroup\$ More that the roll determines what ideas his character has for disabling it, or what his character notices about the trap. So the roll would provide options, rather than determine his actions. \$\endgroup\$ Feb 19, 2015 at 14:02

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