If you're a builder of a dungeon, you want your traps to keep the unwanted people out. You want those who enter to be killed or driven off, and you want to keep yourself safe. But traps also need to be reset. A ceiling that collapses cannot reset itself and will block off that passageway until it is fixed. A crossbow trap must be reloaded.
So what is a Dungeon Planner gonna do? Well, if you currently inhabit your dungeon, the problems are a lot easier to manage. You'll be around to reset traps. You'll know exactly where they are because you have to walk past them everytime you go in and out of your dungeon. You may even have ways to deactivate them.
What I like to do is to build out a sample image of how they might work so that my players, freshly salty from being hit by a trap, can see how they function - presuming they pass whatever checks are appropriate.
What I have for you today is 4 traps that my players in Hardly Heroes will be running up against in their next session. Since this post is coming out before they play, I beg of you not to share any info with them. These traps are going to be set up in a hallway on the way to Steal Team 6's dungeon, and involve a
Our first trap for you is our Axe trap. This one uses a line attached between a door and the handle of an axe as a trigger. When the door is closed, the axe is pulled up to its full height. When the door is opened, the tension that holds the axe is released, and the axe comes swinging down. The trick to get this to work is to use pullies or direction of tension changing devices so that the axe reaches peak height when the door is partially open, and then rapidly loses tension when fully open, so it doesn't trigger too soon.
A trap like this would be easy to line up, and with sufficient weight attached to the head of the axe, deliver a solid blow. In 2e D&D, this would work as at least a +2 to hit as the axe is unexpected and dropping out of the ceiling at the last minute, but its coming from the direction the target is walking. If the person walking through the door were too short, it would miss entirely. If set for a person who was very short, it might have an attack penalty on tall people. Damage would be roughly axe damage (1d8). You could argue that if it was well set up and well aimed, it might have a better to hit, and if it was extra heavy or sharp it might have a slightly higher damage, but generally speaking this is going to be a straight forward action.
The self resetting nature of this trap means it is optimal as your first line of defence.
+2 to hit, 1d8 damageresets when door is closed
+4 to hit, 1d8 damage
The crossbow trap is another classic. Similar to the axe trap in that it is triggered by, and aimed at, an opening door, this trap is a basic attack roll and basic damage die. Considering that you won't even see the bolt coming (short distance, bolt go fast), I'd say this has a better roll to hit, similar damage, but needs to be rearmed and reset which is a pain in the butt for the Dungeon Planner.
A nice thing about this trap is that if it is triggered by a team of short characters, it may miss one and hit a different one behind it. Or if the person in front is super agile and dodges the attack, the person behind them may get hit.
Saving throw to avoid, 1d6 damage per 10' fallen + 1d6 damage for the spikes at the bottom.
Pit traps are classic! The real problem with them is hiding that the floor here is unstable. You could build a big fancy trap with stones that fall away, but that's a huge pain to reset. You could use a floor hinged on one side that drops away when enough weight is on, but it's going to be expensive and you run the risk of someone stepping on it, noticing the change in texture or sound, and stepping off.
What works great is to have a long run of old dirty carpets with one of those carpets covering a pit. If the Dungeon Planner has some little tiny nails or hooks in the floor near the trap, the carpet will hold onto those real well and keep the carpet nice and even over the pit.
The Dungeon Planner may have to have multiple carpets on hand to replace the first one every time it gets triggered, but that's why we use old, dirty, dingy, 5th hand carpets. They're cheap.
PCs may find this one easily just by testing the floor before them.
A trap like this might have very solid ground to either side of the carpet so a person in the know can do some big wide stances to bypass, or just remember which carpet it is and take a little leap across the dangerous part.
+0 to hit, 1d3 damage, many attacks
The dart trap is one of the more awkward traps to make. Because it uses air bags and falling weights to generate the force, the aiming of darts is going to be sort of awkward, and the force they shoot with may not be a ton. They're essentially a whole line of crossbow traps that have poor aim and low damage - but they can be strung together.
For a trap like the above one, it's triggered by a thin tripline attached to a weight. When the tripline breaks, the weight falls and rolls down an incline. It knocks over the next trigger before falling down to a gas bag and launching a dart. A set up like this will have darts shooting out a split second apart.
The problem with this one is resetting, again. If the darts and bags were entirely inside the wall, they'd be a huge pain to reset. Instead, the wall here is open, revealing the situation. Once past the trap, the whole of the infrastructure would be revealed to the trespasser.
Set up time would take ~3 minutes per dart. By the time the 3rd or 4th dart is flying, the target of the trap would probably be reacting, so I think a trap like this is best limited to 4 darts unless the Dungeon Planner is mad with power and has the trigger activate multiple sets of these on either side of the corridor. In that way could you easily rig up 8 darts to attack, maybe even 16.
In this very simple dungeon, our intruders enter from the left and come to a fork in the road. The top door opens into a room just large enough to house the crossbow trap and room to reset it. The bottom door is where the axe trap is set and has a secret panel in the wall to make it look like a dead end. This dual-dead end will hopefully cause anyone who invades to be hit by both preliminary traps.
Once through the secret passageway, there is a carpeted hall. The first trap in this hallway is the dart trap via a trip line. The carpets will hopefully help disguise the tripline, and the tripline will hopefully make the intruder think there's not a second trap under one of the carpets.
If the intruders make it past the secret door and all the traps, they're rewarded with the underground lair and maybe a fight with whoever is down there.
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Traps are hard to do well. They're hard to make fun, and they're hard to make believable. They've got to be designed to kill and should feel deadly too. These 4 should be enough to kill at least 2 normal people, but our Hardly Heroes characters are a little beefier and might be able to slam into all of them and walk away if only Nick rolls well.