Harbinger has a good post discussing the problems with traps in D&D and some potential solutions. It got me thinking about how traps are typically handled in video games as opposed to tabletop. I’ve been playing an awful lot of Spelunky, as well as some Torchlight 2 and Guild Wars 2. The traps in all of these are similar to many other video games: traps that are not exactly hard to notice, but might be difficult to avoid. Where D&D has typically featured “gotcha” traps, where the real trick is just finding them in the first place, in most video games, the only way you won’t notice a trap is if you’re moving really quickly, but the trick is not blundering into it even though you know it’s there.

This post talks about ways to include these “action traps” (Harbinger would probably just refer to them as terrain hazards) in D&D/Pathfinder, but some of the ideas might be relevant to other systems.

Problems to Overcome

The major challenge in using action traps in a tabletop game is that, in video games, they’re more frequently traps for the player, not the character. There’s no question that your character can avoid the trap, if your reactions on the controls are fast enough to tell her to get out of the way. To really capture the feel of this kind of trap, they to some degree need to feel like challenges for the player; it’s not particularly fun to just suffer bad dice luck and fall onto spikes. Interestingly, this was the original method of traps in the earliest forms of D&D. Finding traps was all about paying attention to clues in room descriptions and describing cautious use of ten-foot poles and other tools to proceed safely; ideally, if you fell onto the spikes, it was because you were moving too quickly and not paying attention. It was only with the addition of the Thief and his Find and Remove Traps skill that the situation moved more to the pretty boring “roll to find the trap, now roll to disable it” system we’ve been trying to make more fun ever since.

And that’s the second problem: now that the Thief/Rogue is part of the standard adventuring party, moving to action traps tends to pull his niche right out from under him. The simplest solution in 3.x/Pathfinder is probably just to double the bonus from Trap Sense if you also have Trapfinding; that is, the Rogue becomes the character best at dodging environmental traps. You send him out in front not because he’ll spot the trap before it goes off, but because he’ll pull some Matrix shit and just get out of the way, and now everyone else knows it’s there and can deal with it. If you still have a few “gotcha” traps, Trapfinding works normally.

Once you’re using these traps, disabling them is only rarely about making a skill check. Instead, you’ll often need to do something creative to set them off, jam them up, or block them off. Or you can just avoid them and try not to forget them when you head back later. A lot of these are helped by having wandering monsters or some other kind of time pressure. Sure, you could laboriously lower the Cleric down into the pit so he can safely tiptoe through the spikes and get pulled back up, but ideally you want him to seriously consider trying to swing across because the safe way would take too long.

Monsters and Traps

In any dungeon that has both traps and monsters, you need to consider how the monsters interact with the traps:

  • They’re invulnerable to them: The most difficult for players but the most sensible for a dungeon designed to include mobile inhabitants, some creatures can ignore some traps. Fire traps with fire resistant creatures, gas and water with creatures that don’t need to breathe, and any kind of kinetic trap with incorporeal creatures are all ways to really up your combat traps to player-annoying levels.
  • They’re vulnerable but aware of them: Any kind of intelligent but not super powered creature that chooses to live in a trapped dungeon should probably know how to avoid the hazards. They’ll typically set up in ways that they can make ranged attacks from across the traps or try to shove heroes into them, but if you can turn the tables they can die to their own defenses.
  • They’re vulnerable and unaware of them: This is most common for unintelligent monsters that weren’t originally meant to be in the dungeon (or just this part of the dungeon), or intelligent monsters that just got here recently (or were lured here by the PCs). This kind of interaction is most appropriate early on (to warn the players that traps are in this area when a monster blunders into one) or toward the end (when players have been slowly earning trap mastery over the dungeon and now deserve the opportunity to turn the traps on the enemy).

Methods of Use

In Combat

Combat use of action traps is the easiest place for them to shine. They typically take the form of “bad things happen if you move into/past this particular square.” Often they’ll do something as an immediate action, but some things might be timing puzzles (see below) that, in combat, mean essentially “don’t end your turn here.”

These are completely adequate for 3.x/Pathfinder’s Bull Rush and other repositioning maneuvers, and 4e has even more methods to shove targets around, but you can make them even more dangerous and fun by introducing the idea of getting casually knocked back into traps when you’re hit. Under this system, any square adjacent to an action trap isn’t safe to stand in; while you’re standing still on the grid, in actuality you’re moving around a lot and a hit might force you to put a foot wrong and stumble in. Whenever you take damage in one of these squares, make a Reflex save with a DC equal to the damage taken or trigger the trap/fall in (that’s the simplest option; you can probably work out a more complex option that better tracks the standard Reflex bonus vs. damage taken at a particular level).

Navigation Hazards

Outside of combat, the heroes theoretically have all the time in the world to figure out how to bypass normal action traps that are just in the way of forward progress. This is the best place to introduce some kind of time pressure as discussed above. In a dungeon that’s not meant to be a long-dead tomb, these are also good to use for ways to bypass certain areas (e.g., if you get across the spike pit, you don’t have to fight through the barracks), so if getting past them safely is more work than just taking the other route, it remains an interesting choice.

One interesting way to set these up is to have them be relatively easy to disable, but with a consequence. The simplest form of this is “you can just trip the trap, but it might be loud and alert the next room.” Another option is situations where breaking the trap has follow-on mechanical consequences: triggering the dart with a stick means it hits the treasure/explosives/captive/currently-docile-monster instead of you, jamming the mechanism that rewinds the blades may cause them to violently tear free of the wall, etc.

Timing Puzzles

Situations like the Breath of God from Indiana Jones and the Last Crusade and the Chompers from Galaxy Quest are perhaps the hardest to do well in D&D. These are traps that trigger in a regular sequence, or moving past one sets off another requiring you to quickly move past, and so on. Traditional round-by-round action makes these almost unusable: either they interrupt as soon as you move into their threatened area, or you can easily move dozens of feet as one action before anything else gets to go. Just turning them into a skill challenge where you have a series of rolls to jump and tumble is possible, but removes most of the player skill aspect of the traps.

A solution may be to essentially speed up rounds when bypassing these hazards to half a second or so: you can move five feet per round at a full move if you’re at 20 ft or 30 ft speed. While you can still jump more than five feet, each five feet of the jump takes a round (during which you’re in midair with limited ability to dodge hazards). The active player goes, then the traps go, and in fractions of a second whole squares may be essentially impassible (e.g., “there’s a giant blade swinging in this square right now, if you enter it, you’ll automatically get hit”). The player choice should come from certain squares being safe for a couple of rounds, multiple paths through the hazards, and somewhat-predictable randomness to the hazards. If done well, it would be an incredibly memorable encounter; if done poorly, your players may become Gwen DeMarco shouting, “Whoever wrote this episode should die!”

Example Traps

Taken mostly from Spelunky (which means they’re mostly from Indiana Jones), but also cribbed from other games:

  • Spikes and Pits: No need to hide these under a trapdoor; a spiked pit is threatening even if totally uncovered if it’s big enough to be hard to clear or lurking on the edge of a combat area. A spiked wall isn’t just for the impossibly goth as long as there are things that might push you into it.
  • Shooting Traps: Triggered by some kind of obvious floor plate or just getting within a certain range, these are often darts but could be some kind of magic bolts. They’re often the hardest to justify if there’s no active maintenance to reset them, but they have the greatest reach. Keeping an eye on these is important since they can hit you anywhere in the room.
  • Proximity Traps: The easier-to-reset version of the shooting traps, these are spikes, blades, bludgeons, or energy jets that spin or shoot out into a defined nearby terrain. They may respond to proximity (hitting their target squares immediately or after a delay when someone steps in) and require time to reset (but reset automatically) or be on a regular (or randomly regular) release/reset cycle.
  • Trapdoors: A trapdoor doesn’t necessarily have to be a “gotcha” trap to be dangerous. They can also be perfectly serviceable as floors for a few moments or until something else happens to trigger them. If there’s nowhere else safe to stand, the space that’s going to be unsafe in a moment may be the best option right now.
  • Crushing Traps: Perhaps the hardest to reset, these have the greatest potential for mayhem: from a rolling boulder, to the classic collapsing ceiling, to more-targeted thwomps. These are often saved for areas where you no longer care about the structural integrity of your dungeons; if an invader’s gotten this far, you want to pulverize them no matter the cost.
  • Surprise Monsters: As long as they’re something that makes sense to sit in a box indefinitely, surprise monsters that pop out can be exciting. What stops this being a “gotcha” is that you establish that sometimes these types of boxes have a treat, and sometimes a trick, and it’s up to the players whether they want to risk smashing them all open to see what falls out.
  • Surprise Bombs: Even if you don’t have gunpowder, magic can substitute in a pinch. The important thing is that these have a “fuse;” when one pops up, it’s less about getting instantly annihilated and more about whether you can finish up what you were doing in the room before it becomes so much scrap, and whether you’ll push that time limit.
  • Water: Water is exciting because it’s not necessarily directly lethal, but it can certainly be full of lethal creatures. Falling into water often severely limits mobility for other problems to occur in a moment. And if you’re in it for too long, particularly if a lid closes on you, you have to worry about getting out before you drown. If it falls on you, it’s a combo water and crushing trap.
  • Lava/Acid: It’s like water, but it kills you pretty much instantly! And it destroys items that fall in, which may hurt even more. This is way harder to justify in any kind of realistic game, except in some very rare locations, but can really step up the danger when you can include it.
  • Immobilizer: A field full of bear traps is a problem even if you’re not worried about breaking an ankle. You might be menaced by a mountain lion! A trap that immobilizes even for a few moments increases the danger of other traps and monsters in its vicinity.
  • Darkness: Not exactly a hazard in and of itself, the ability to turn out the lights (either supernaturally or just with a sudden gust of air that may blow out torches) makes all the other traps (and any creatures that don’t need light to attack) much more threatening. Normally-well-lit areas that randomly (or on trigger) turn pitch black can really complicate a seemingly simple navigation hazard or timing puzzle.