Type: magical; Perception DC 28; Disable Device 28
Trigger location; Reset None
When the PC’s get about halfway down the corridor, the entire area becomes bathed in bright light. Light Bomb(DC 19 Fortitude Save or become blinded for 1d4 rounds, those that make their save take a -2 penalty to vision based checks for one round); multiple targets (all targets within 60 ft)
There are several options for what comes after this trap. Of course, the obvious course of action is to use this trap as the opening gambit in a surprise attack. This can be used a few other ways, though. It can disguise another trap, help hide a secret door or just be used to diminish the advantage of a party with darkvision. It would also work well as a distraction for a fleeing NPC. As a last resort, you could just use this on its own, and watch the paranoia start.
A small fountain sits in the center of the courtyard.
Type: magical; Perception DC 29; Disable Device 29
Trigger Proximity; Reset None
When a PC gets within 10′ of the fountain, the water churns and splashes outward. When a PC is splashed by the fountain they are imbued with 1d10+7 temporary hit points that they are not aware of. These hit points will be lost first. To the PC, it will be as if he was not damaged until they run out. However, once they run out and the PC actually takes damage, he will also take additional damage immediately for the amount of temporary hit points he was granted. Fountain Splash(DC 21 Reflex Save avoids); multiple targets(all targets within 10′)
This one will work especially well if you don’t tell the PC’s anything happened when they get splashed. Just secretly roll up the temporary hit points, and next time they are in combat use them. You can describe the action, “You get hit with an axe. It penetrates your armor and bites into you flesh, but you seem to shake off the wound as if nothing happened.” They probably won’t know why they aren’t taking damage, but they won’t question it. However, once the hit points run out, make sure to describe what happens. “You take a glancing blow, but suddenly, wounds appear and begin to bleed profusely as you slip into unconsciousness”.
They still may not put it together, so you may have to use this again, and again… At any rate, once they figure this out, every time something minor happens, the players will suspect the worst. You can use this to build tension or to bring another layer of action to life in your adventure.
One good way to keep your players on their toes is to present some classical traps in new ways.
Fan Pit (CR 6)
The floor of this long hallway is made of wood. A glass window is in the center of the hallway.
Type: mechanical; Perception DC 22; Disable Device 19
Trigger location; Reset None
If the window is opened, the fan activates, pulling the character down into the pit. The pit drops 10 feet into a fan, and then another 20 feet. Pit (DC 22 Reflex Save or take 3d6 damage, +12 melee attack or take 4d8 damage from fan)
With the simple addition of an element (the fan) a normal trap takes an unexpected twist. By adding the fan, you’ve added an extra layer to a familiar trap. If you do this early, you can use this to help set up later encounters and elements, especially if your party has fallen into an exploration rut. This just might prod them to probe on layer deeper, which opens up your plot and design possibilities.
Some traps aren’t really traps at all, but are part of the landscape that end up with trap-like effects. For example:
Goblin Privy (CR 2)
A small wooden door is set into the wall.
Type: mechanical; Perception DC 18; Disable Device 19
Trigger location; Reset None
When a PC opens the door, the sight and smell of the room beyond is… sickening. Goblin Privy (DC 18 Fortitude Save or become nauseated for 1d6 rounds); multiple targets(all targets within 30 feet)
Think about all the rooms and equipment that might be in your dungeon, whether it be an ancient Dwarven underground fortress, an illithid lair or goblin stronghold. Hazards, both lethal and non-lethal, are likely to be behind lots of doors. Rather than either having lots of empty rooms or just a few rooms, add some character into your dungeon that doesn’t just have flavor text, but also has concrete effects. Remember, even goblins gotta pee somewhere, too.
Sometimes, you use a trap to help your PC’s, giving them a taste of what is ahead.
Scorch Marks (CR 2)
Opposite the door are scorch marks on the wall.
Type: mechanical; Perception DC 18; Disable Device 17
Trigger location; Reset Repair
When a character gets within 15′ of the door, a timer starts. If they do not open the door within 2 rounds, a gout of flame shoots out from the door. Flame(DC 16 Reflex Save or take 1d4 fire damage); multiple targets(all targets in 15′ cone)
This is a good trap to have near the beginning of your adventure. Why? Most traps help set the tone of your adventure. In this case, the characters who take their time will get burned (literally). It won’t do much damage, but it will help you set up later encounters, especially if they are time critical. Having been burned once, PCs are less likely to dilly-dally. If you do have time critical encounters, this trap will also prepare your PCs, giving them a greater chance of success, which is, after all, much more fun for everyone.
Several armchairs have been placed around the room. They all seem to have overstuffed cushions.
Type: mechanical; Perception DC 28; Disable Device 16
Trigger Touch; Reset Repair
Just under the cushions are several sharp, barbed spikes. Spikes (DC 18 Reflex Save or take 1d3 damage and become entangled with the chair. DC 22 Escape Artist or DC 22 Strength check to free from chair, however, if Strength is used, an additional 1d3 damage is dealt)
If you offer the PCs food or drink, of course they will be suspicious. But who is wary of a comfy chair? This would be a perfect beginning to a combat encounter. Several of the characters sit in the offered chairs, and become stuck as guards or thugs arrive. You can always poison these things, too. This trap can also make future social interactions somewhat awkward for the PCs. A host could take offense at the PCs poking and prodding the furniture before they sit down. The PCs may even refuse to sit down, further offending the host.