We talked about hidden traps a few strips ago, and the problem they cause: namely that they make players paranoid and slow down play while their characters exhaustively search for traps.

Traps are actually fundamentally problematical for a roleplaying game. Traps work in traditional fiction because you can always have your protagonist be just paranoid enough when they need to be, and get on with the story when they don't need to be. And of course you can always control the danger and lethality of a trap in a traditional story so that the protagonist is dramatically threatened but can escape.

It's tempting to try to simulate cool traps in a game. But you don't control the players. So, firstly, they have no idea where and when they need to expect and look for traps, and when they can safely ignore the possibility and just get on with the adventure. Playing safely bogs down the action, while playing more loosely and getting on with the story risks lethal danger.

Secondly, how do you mechanically handle searching for traps? Games have evolved at least three different options:

1. Players must actively announce a "search for traps". They then get some sort of observation/detection roll against a skill or attribute. If the dice roll succeeds, the GM tells them they found a trap, if it fails, the GM tells them they didn't find anything. This is one of the oldest approaches used in many classic adventures from the 1980s to 2000s. The problems with this approach include: (a) it encourages game-slowing paranoia; (b) if the player gets to roll dice, they know when they failed to detect something; (c) on the other hand if the GM rolls the dice in secret and says they characters don't detect anything, they will remain suspicious that there may be a trap and potentially continue slow play.
2. Players have a "passive observation" score. The GM secretly applies this to the obviousness of any given trap, and either rolls in secret or simply notes if the score exceeds the trap's detection threshold. On a success, the GM tells the players—unprompted by them—that they notice a trap, or something suspicious. On a failure, the GM simply doesn't tell them anything, and lets them blunder into the trap. Dungeons & Dragons 5th edition uses this approach in many published adventures. The problem with this approach is that it takes away player agency. The GM is simply determining success/failure in detecting the trap and the players have no say whatsoever about it.
3. The GM describes a location in enough detail that players can look for traps by stating that their characters physically examine specific sub-locations or manipulate specific items. For example, the GM may describe a fireplace, and then the players may need to specify that they examine the flue, the firescreen, the sides of the mantelpiece, or the inside surface of the chimney in order to discover the trap trigger. This is a more organic approach, but: (a) it relies on the players being observant and clever rather than their characters, and (b) it really slows down play.

So how can traps be used in a game in a way that gives the players things to do, without making them paranoid and taking forever to examine every game location, and also utilising the skills of the characters? One radical option is to not have traps at all! Games don't really need traps, especially if the adventure plot is political or simple gung-ho monster fighting. However traps are a genre feature in traditional dungeon exploration adventures.

Another approach is to make traps more or less obvious, and then let the players/characters figure out how to not get caught in them. The GM can simply announce the presence of a trap or a likely trap, and the roleplaying challenge is to work out how to get past/through the trap without suffering the ill effects. This turns the trap into more of a puzzle - a puzzle with dangerous or deadly consequences. So it still feels like a trap, but the players don't need to be paranoid to detect it in the first place, and their characters get plenty of agency to decide what to do about it.

As a simple example, the players are exploring a corridor, when they notice a net hung from the ceiling. It looks rigged to drop on them as they walk beneath it. There's no way around, and it's not clear what the trigger mechanism is. The GM just announces this information, and lets the players decide what to do. They could look for a trigger and try to disable it, they could mechanically prevent the net from dropping, they could use magic to fly down the corridor without touching the floor...

Transcript

GM: There are... legends like the Moon Ghost, but most people dismiss such things as superstition.
Rey: Hmmm. So probably a physical trap. I examine the chest for needle holes, or odd wear patterns.
GM: <roll> You don't see anything like that.
Rey: I open the chest slowly, listening for any clicks, prepared to jump away.
GM: It opens easily, revealing folded clothing, trinkets, and lying on top, a laser sword.
Rey: This is too easy. There has to be a trap here somewhere. But where?
Rey: All right, I pick up the laser sword.
GM: Not so fast! You reach out and your finger touches the sword—
BB-8: The sword is the trap! You’re probably losing a hand!
Rey: I knew being a meatbag was a bad idea.