Introduction
Dungeon traps are a staple of old school dungeon design. They come up in basic rooms 5% of the time (1/20) by themselves, they can come up on treasures, on trapped door, during ambush, etc. and are sometimes, in modules, the focus of some rooms. Whole books have been written about tricks and traps in dungeon.
That being said, sometimes they are basically either a nuisance or a deadly “save or die” threat. I like my traps to be telegraphed A LOT. The reason for this is not to make it easy on the players, but to tell them "there might be a danger here", in order to engage them in the fiction and make them think as their character. They don't know if it's a trap, a monster, or a trick, but they know there is danger. They still have to find the trap intelligently and disarm it, sometimes getting killed in the process, but that's up to them. I prefer this than having anything that either slow down the game (having someone poke non-stop everything with 10' pole), or force my players to inaction (having suspected traps everywhere without a guess on where it can be will diminish player's interaction with the dungeon, not enhanced it IMO), or play Yatzhee (everything “fiction” becomes a dice roll). To do this, I will have both traps and elements that will help to reveal it if the players are picking them up, such as trigger, danger zone, corpse, detritus, active warning and other signs of the same type. I will be honest, I do not remember where I took this system: another blog, a book, etc. ? Whoever it is, credits to you.
There is a lot of good OSR blogs with traps and stuff taken sometimes as "obstacles", and especially old school resources that deal with. You can also search only for interesting "challenges" instead of traps. Maybe I'll do something on challenges at one point. There is also some youtube challenge with puzzles that can be used sometimes as challenge/traps.
Also, I like my traps to be like monsters. First time you encounter a Medusa for example, you might be in for a world of hurt. But if you acquire the right item, and/or can fight blindfolded, that knowledge of combat by the players can save them and make the challenge easier. Their character level increase but also their knowledge of the world. For that reason, I try to put very few types of traps and focus on copy-pasting them, based on either monsters making them or architecture (i.e. each ancient culture favored some traps). That way, players with experience can expect some kind of traps in a type of dungeon (I'll be honest, they rarely do, but at least it's out there for them to do so).
Disclaimer as I always do. What I present here is not something I find "better" than what is presented in old books. Rather, it's just better suited to my needs, and it's influenced by it.
Traps
This is my "base list" of traps that I use. Some will force you to reconfigure a bit the rooms. But I like this iterative idea where my room will change as I add stuff in it.
Trap Type (d10)
Slicer
Poison Spray Shower
Sleeping Gas Chest
Spiker Roof (aka Predator Trap)
Snake Pit
Crushing Hallway Boulder (aka Indiana Jones Trap)
Dart Trap
Pit Trap (10’ deep with spikes)
Recessed Arm Scythe (generally protecting a door)
Wall Spears
Then, I roll a d6 (or more than one) to determine what kind of “danger signs” the player can find.
Danger Signs
Trigger
Danger Zone
Corpses
Detritus
Active Warning
Other Warning
Each is connected with its trap, such that:
Other Traps and Random Points
But there are other traps you can have:
Creature Trap: Traps that make creature pop up, ambush, open a gate, portal, etc.
Explosion: As the name implies, like an explosive attached to a rope that drops when a door is opened
Falling Objects: Falling block of stones, etc.
Gas and Potion: Have your humanoid attach gas potions to ropes at shin level that the players WILL knock down without looking and be drown in acid (true story)
Fog: You can have those do plenty of stuff, like being a normal fog (will still scare player), a "random emotion fog" (can trigger them into confusion), poison gas, etc.
Illusion: Illusion floor that makes you drop to your death is a classic I'd say
Light: Flashbang
Alarm: What worse than having the whole dungeon now getting to you ?
I also like having tricks or traps that deal other effect than death, such as:
Ages 10 years
Reset other traps
Animate the weapon of the bearer to attack him (it was fun, true story)
Causing a magical "cancellation" on all object of bearer for X hours
Enlarge/reduce
Teleport elsewhere in the dungeon
Become invisible, mute and paralyzed
Change the configuration of the dungeon
etc.
Tricks
Tricks are stuff that look like they can be interacted with (magic item, chest, trones, etc.) but can be problematic for the player if they are too curious or not cautious enough.
You could have your tricks fall under some classic categories, such as (d12):
Bait: Part of a monster, crown on a pedestal, etc.
Boon/Bane: According to the alignment and class, something that grants a positive and a negative
Confusion/Misdirection: Golden platter but with yellow mold; a big monster that’s actually a weak one; a medusa as a crying woman; a golem covered in gold (that looks like a statue worth its fair share); etc.
Defended: Animated furniture, room that fills with water when you touch the treasure, etc.
Puzzle: Stone statue missing an eye a reveals a passage (why not have a faction of monsters stole it for more interaction?)
Question: Statue/book/NPC Ghost/etc. that indicates a clue on how to vanquish a monster elsewhere in the dungeon; a door that needs a magical key; etc.
Secret: A hidden secret that could be revealed later because the mecanism will be found on another same-type secret further in the dungeon (meaning player could decide to go back to unlock it when they learn about it), e.g. a statue that when turned opens something and later the player finds the same statue turned with the thing opened
Shiny: Something nice that does nothing
Tools: Does something neutral (ex: putting a rough gem transform it into a perfectly cut one, a statue that repeats what you say in another obscure language, etc.)
Transmutation: Modified reality (water sharp like razor, false food, etc.)
Transport: Teleport elsewhere (horizontally or vertically)
Treasures with a twist: Maybe the gold will melt under the sun?
Or you could create your own kind of trick randomly by adding an ‘Effect’ to a ‘Feature’:
Effect
Age 1d10 year
Animate itself
Animate the user weapon
Appear/Disappear (either itself or the user)
Antimagic (in the room or around it)
Electric shock
Ask a password to do something
Direct towards …
Enlarge/Reduces itself
Enlarge/Reduces the user
Flesh to stone
Gaseous
Greases
Greed-Producing
Release coins/gems
Release a magic item (cursed?)
Slide across the room
Teleports
Reduces/Inflates HP/Stats
Remove magic from an item (for a time)
Feature
Altar
Arch
Ceiling
Fireplace/Fire
Fountain
Fresco/Mosaic
Idol
Illusion
Machine
Pedestal
Pillar/Column
Pool
The Room
Statue
Vegetation
Wall
Well
Furniture
Force Field
Door
Conclusion
Traps and tricks can be fun, but especially if:
a) they lead to something else that can be conductive to play, engagement and fun
b) are telegraphed just enough that players have to PLAY the challenge instead of passively receiving it
This is in-line with GFC's take: https://www.youtube.com/watch?v=k2MCEcPSAzQ&t=4s
Also, the dolmenwood advice on finding traps is very strong:
> In enclosed spaces, hidden features can often be located by narrative interaction (p150). Alternatively, players may declare that they are searching a certain object or 10′ × 10′ area for hidden features (e.g. traps, secret doors, hidden compartments, etc.). The Referee rolls a Search Check.
Time: Each search takes 1 Turn.
> Multiple characters: If space permits, multiple characters may search the same object or area. Up to 3 characters can simultaneously search a 10′ × 10′ area.
Retrying: Characters may search the same object or area again as often as they wish, each attempt requiring an additional Turn.
> Referee rolls: The Referee rolls all Search Checks, so that players do not know if the roll failed or if there are simply no hidden features present.
Then, Narrative Interaction states:
> The basic game procedure serves as the fundamental means of interacting with hazards and challenges. The environment is described and clarified with questions from the group, then the characters act and the Referee judges what happens. Sometimes a die roll is required— putting a character’s fate in the hands of chance—but it is often possible to bypass hazards using ingenuity, without any kind of random roll.
A big part of what I do in my module auditing process is make sure that every hidden thing has some sort of tell. The game is a conversation, and stuff that the GM doesn't mention effectively doesn't exist for the players. If you force them to say "does the floor have any uneven stones" or "does the wall have any holes" or "is there anything on the ceiling", in order to get that information, then they will learn to ask that *over and over*. It's way better, imo, to make things have some sort of tell.
For everything that doesn't have a tell, I like giving a 5e-style passive perception checks (1-in-6 for humans, 2-in-6 for most demi-humans, TR skill for thieves). If they're unlucky and still don't notice it, traps only have a 2-in-6 chance to trigger per potential triggering opportunity (like for each character walking over a pressure plate).