Making Dungeon Traps

INTRODUCTION

Traps in dungeon are important. They come up in rooms 5% of the time with a treasure, and can also come up as a trapped door or an ambush. 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". 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, even if I know I will get FOE with this), 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). 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 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 don't, 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. The reason the elements of the trap are numbered is because I will make those more obvious. Not necessarily visible outright, but at least observable or noticeable. So everytime I put a trap in a dungeon, unless I already have an idea of the room and what would be more appropriate, I roll d6 to determine the element to be put in place. In theory, I could put more, and I do sometimes, especially since the trigger is supposed to be present in any cases. Those make 10, so it's d10 to generate.

	Name	Trigger 1	Danger Zone 2	Corpses 3	Detritus 4	Active Warning 5	Other Warning 6
1	Slicer	Pressure plate	Lenght of hallway	Sliced	Sliced rats	Niches with scythes	Distant woosh noise in the room prior to this one
2	Poison spray shower	Lever	10 ft square	Agonisingly melted	Melted helmet	Acid pits on floor	Bad smell in room
3	Sleeping Gas chest	Switch in the chest	Room	Sleeping rats in the corner	Dead rats that die of malnurishment	Small holes in the bottom of the wall for the gas	Strange smell in the room
4	Spiker roof (aka Predator trap)	Tripwire	5 ft, human height	Spiked skeleton on the floor	Wooden chip and spikes nearby	Hidden spikes on the other side of the trap on the ceiling	Light coming through that can make the spikes or wire apparent
5	Snake pit	Pressure plate	At the bottom of a staircase	Bitten/poisonned corpse	Corpses of snakes outside of it	Small plate on the walls, small holes in the floor	"Hissing" sounds
6	Crushing hallway boulder (aka Indiana Jones)	Pressure plate	All corridor, up to 100'	Crushed skeleton	Hugeass rock at the end of it	Opening at the end of the hallway on the ceiling	Dark stain on the floor, rock chipping on the walls
7	Dart Trap	Proximity (magical)	5' in front of the object it protects	Skeleton with little darts around	Darts on the ground	Tons of small holes beside the objects	Detect magic
8	Pit Trap 10' deep /w spikes	Lid (150lbs)	10' square	nil	Torch lying on the ground (whoever fell last dropped it)	Lines and creaks on the ground	Floor will wobble at 149 lbs and less
9	Recessed Arm Scythe (protecting a door)	Latch (pull in a hole to "open the door")	Hand is chopped	Hand corpse	Instruments use to pull it chopped	There is another small hole to actually put a key in it	There is a hole up of the level (where the blade comes through)
10	Wall spears	Tripwire	Side of a wall	Speared skeleton	Wooden shaft on the ground	Holes on the side	Wind coming from the wall (holes are letting it through)

OTHER TRAPS AND POINTS

But there is other traps you can have:

• Creature trap: trap that make creature pop up, ambush, open a gate, portal, etc.
• Explosion: as the name implies
• Falling items: falling block of stones, etc. 
• Gas and potion: have your humanoid attach gas potions to ropes 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
• 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 and not cutious enough. 

You could have your tricks bound to something else interesting, such as:

	TYPES	Example/Description
1	Bait	part of a monster, forcefield crown*, etc.
2	Boon/Bane	according to the alignment and class, something positive and negative
3	Confusion/Misdirection	golden platter with yellow mold, monster not what it appears, medusa as a crying women, golem covered with gold (looks like a statue), etc.
4	Defended	animated furniture, fill with water, etc.
5	Puzzle	stone statue missing an eye that reveals a passage (a monster stole it), etc.
6	Quest	statue/book/NPC/Ghost that indicate a clue on how to vanquish a monster elsewhere in the dungeon, a door that needs a magical key elsewhere in the dungeon, etc.
7	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 it)
8	Shiny	somthing nice that does nothing (ex: a dragon skeleton within a crystal)
9	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.)
10	Transmutation	Modified reality (water sharp like razor, false food, etc.)
11	Transport	Teleport elsewhere
12	Treasures	Treasures

Or you could tie them to features and effects (both column are not linked, you can roll d20 for each and apply as per). 

	Features	Effect
1	Altar	Ages (1d10 year)
2	Arch	Animate itself
3	Ceiling	Animate user weapon
4	Fireplace/fire	Appear/Disappear
5	Fountain	Antimagic (in the room)
6	Fresco/mosaic	Electric Shock (1d10 dégât)
7	Idol	Asks password
8	Illusion	Directs towards...
9	Machine	Enlarges/Reduces itself
10	Pedestal	Enlarges/Reduces user
11	Pillar/Column	Flesh to stone
12	Pool	Gaseous
13	Room	Greases
14	Statue	Greed-producing
15	Vegetation	Release coins/gems
16	Wall	Release magic item
17	Well	Slide
18	Furnishing	Teleports
19	Force Field	Reduce stats/HP
20	Door	Remove magic from item

CONCLUSION

Traps and tricks can be fun, but especially if 

a) they lead to something else that can be conductive to play and fun

b) are telegraphed just enough that players have to PLAY the challenge instead of passively receiving it