Wednesday, August 3, 2011


Traps are fairly ubiquitous to site-based adventures in Dungeons & Dragons. I can’t recall a single adventure module that does not contain at least one “trap” to catch the unwary adventurer by surprise, and some published adventures pride themselves on the fiendish devices they are reputed to contain (the Tomb of Horrors being one of the more notorious).

And yet, I’d argue that traps are, in the main, poorly defined as to what they are and the purpose they serve in the game AND that their purpose and design has changed considerably from edition to edition. So much so that they actually change the STYLE OF PLAY depending on the edition you’re playing.

Now I realize that some might disagree with that last statement…fine, yes you’re right. I know I’m not going to convince you otherwise just as I know I’m not going to convince those folks who say D20 or 4E can be played in an “Old School” fashion, or those that say “system doesn’t matter so long as you have the right GM for the game.” I’m not interested in a dog-fight here…I’m just trying to have a conversation about design, okay?

So having prefaced that, let’s talk:

OD&D (from Volume 3, page 6)

“Besides those already indicated on the sample level, there are a number of other easily added tricks and traps. The fear of “death,” its risk each time, is one of the most stimulating parts of the game. It therefore behooves the campaign referee to include as many mystifying and dangerous areas as is consistent with a reasonable chance for survival (remembering that the monster population already threatens this survival). For example, there is no question that a player’s character could easily be killed by falling into a pit thirty feet deep or into a shallow pit filled with poisoned spikes, and this is quite undesirable in most instances.”

Here we see the idea that traps are to be used to stimulate the players’ adrenaline, without actually proving deadly…most of the traps listed are ones designed at disorienting or transporting PCs, apparently in aid of keeping them lost and guessing in the mega-dungeon environment. Traps are thus used mainly to keep players OFF-BALANCE.

HOLMES Basic D&D (page 40):

“Wandering monsters are usually determined randomly as the game progresses. Traps should not be of the “Zap! You’re dead!” variety but those which a character might avoid or overcome with some quick thinking and a little luck. Falling into a relatively shallow pit would do damage only on a roll of 5 or 6 (1-6 hit points at most) but will delay the party while they get the trapped character out. Hidden rooms, movable walls, teleportation devices, illusion rooms, dead ends, etc., make interesting variations.”

Father Dave has spent much time devoted discussing the workings of the Holmesian Underworld and I tend to agree with his analysis that traps in Holmes D&D are used in the main to trap or delay adventurers, such that the inevitable wandering monsters spawned by the dungeon will catch up to the party. None of the traps described in the sample adventure are damaging by nature…they knock PCs out or render party member unconscious or force characters to dis-armor themselves, all of which make the party more vulnerable to wandering monsters. The traps are used to SET CHARACTERS UP for dangerous monster encounters.

AD&D (from the PHB, page 103):

“Traps are aimed at confining, channeling, injuring, or killing characters.”

Gygax then goes on to explain these four kinds of traps, where they are usually found, and their purpose, as well as some possible methods of mitigating them. Regarding killing traps, he states:

“Killing traps are typical of important areas or deep dungeon levels. Deep pits with spikes, poisoned missiles, poisoned spikes, chutes to fire pits, floors which tilt to deposit the party into a pool of acid or before an angry red dragon, ten ton blocks which fall from the ceiling, or locked rooms which flood are examples, of killing areas. Again, observation and safety measures (poles, spikes thrown ahead, rope, etc.) will be of some help and luck will serve as well.”

While the descriptions of confining and channeling traps seem right in line with OD&D and Holmes, injuring traps (which sap the party’s strength) and especially killing traps are something new entirely. However, the USE of these “killer traps” appears to be confined to areas of importance or “deep dungeon levels” (i.e. reserved for high level characters. Where parties find them, they can expect rich rewards (or adventure objectives) to be nearby. In this instance, traps can serve as MARKERS and CLUES for the adventurers, telling them a bit about the area into which they’ve stumbled, based on the type of trap encountered.

D20 (from the DMG, page 112):

“In a dungeon, adventurers can fall to their deaths, be burned alive, or find themselves peppered with poison darts – all without ever having encountered a single monster. Dungeons tend to be filled with barriers or life-threatening traps of one kind or another. The following sections lay down some basic rules for handling common obstacles and traps.”

And now we come to the opposite end of the spectrum from where we started. In D20, all traps are dangerous (damage-causing) hazards. Period. If a dungeon feature can kill you, it’s a “trap;” if not, then it’s something else (shifting rooms/corridors, elevators, and teleporters are all listed as “miscellaneous features” of a dungeon, rather than traps). In D20, traps are static ENCOUNTERS to be triggered and (hopefully) survived. Unlike earlier editions, PCs gain XP from surviving traps, so it is in the adventurers best interest to find and set-off as many as possible. As with any other game, reward mechanisms encourage behavior, and D20 awards XP for fighting monsters and surviving traps…only. D20 encourages direct confrontation and conflict, and traps are a way to (as the sidebar says) “change the play of the game.” As with monster encounters, traps are something to be defeated and overcome, but they force the party to slow down and approach the challenge in a different fashion from standard (monster) encounters.

So there…four different editions and four very different takes on what a trap is and how to use it. Of course, I don’t play any of these editions, but instead B/X…the King of Games. What about B/X?

Moldvay actually has very little to say about what a trap IS (and the Cook/Marsh Expert set doesn’t broach the subject at all):

B/X (page B22):

“Dungeons often contain traps, such as a trap door in the floor which springs open when a character walks over it.”

That’s it. Moldvay goes on to explain how traps are triggered and how they are discovered, but no mention is made of their purpose or how deadly they are…does the trap door mentioned lead to a spiked pit? Or a chute to the next level? Who knows…there’s the same chance it could lead to a feather bed or a bed of lava!

What we do know is the presumed frequency of traps: 1 in 6. That is the chance of a trap being present in a room’s contents (page B52). A dungeon with 24 rooms should have traps in four of those rooms.

That’s a lot.

From the suggested traps listed, one can see Moldvay considers traps to be nearly as ubiquitously hazardous as D20:

Poison gas: Save vs. Poison or die

That’s the first trap listed…a cloud of nerve gas that wipes out the party. Remember, B/X gives rules for running LOW level games (1st through 3rd level characters); these are not PCs with neutralize poison and raise dead spells or rings of wishes. Of the other five “room traps” listed, three cause damage (two without saving throw), and one drops the character to the next level, probably dooming him to death.

Moldvay also lists some suggested “treasure traps:”

Poison needle: Save versus Poison or die

Yep, once again, “auto-kill” is first on the list. Of the other five traps in this category, one is a poison snake, one does up to 24 points of damage (enough to kill your average 5th level fighter), one blinds the victim for D8 turns and another doubles the character’s chance of encountering wandering monsters for several hours.

None of the traps listed in Moldvay are confining, or shifting wall-related.

In fact, of all the editions I’ve perused, the B/X Basic set has got to be the hands down deadliest with regard to its take on traps. Gary and Dave’s talk of instant death traps being “undesirable?” Holmes statement that traps should NOT be the “Zap! You’re dead!” variety? Pretty obvious that Moldvay is on a different page from these early works.

And as far as Gary’s “Advanced” take, that killing traps are only found in important areas or deep dungeon levels? No way. The “sample dungeon expedition” (page B59) has a deadly poison needle trap stashed on a box containing 2000 silver pieces. That’s worth 200XP to the surviving party members (four of ‘em, or 50XP each). Only 39 more “scores” like that for the fighter to level up to 2nd level. Presuming they don’t run out of thieves.

[to be continued]

[edited to fix the f'ing formatting...damn library computers!!]


  1. I think Gygax defined what traps were for when he wrote Tomb Of Horrors in 1978.

  2. @ TS: Thanks! More to come...

    @ By the Sword: I think all the "special" modules (S1-S4) were coded as such because they purposefully broke rules of the game. Other modules of Gygax (including his famed GD series) aren't nearly as trap heavy in comparison to monster encounters.

  3. In my 3E game, I RARELY use mechanical-style death/damage traps. Instead I design trap encounters that make players stop and think about how to circumvent them (or traverse them in relative safety), and then toss complications into the works.

    For example, a room filled with a pool of dark water (no one knows what it might contain) and a passage on the other side. Swimming across would require removal of armor and then a way to transport the armor across. Running a rope bridge across increases vulnerability of each person as they cross and spreads the party out. Regardless of the choice the party makes, throwing a monster in at a vulnerable moment adds a huge element of excitement and challenge to the encounter, and allows you to use monsters that aren't toe-to-toe challenges for the players all the time, retaining a lot of excitement and variety in terms of monster types encountered.

  4. @ Taketoshi: Do you assign CRs for these "traps?"

  5. Ugh, CR is something I never, ever use.

  6. Yeah, CR is merely a guideline the DM can use to roughly gauge encounter difficulty for a particular party. Naturally, sandbox style games don't need to worry about this at all. ;-)