Morgrim's Traps and encounters - Part 1 #

From the Dread Lord Morgrim's tome of Phylactery Defense comes advice for devious traps for any prospective Lich, Demon or Dungeon Master. Perhaps these inspire deadlier traps still.

Duergar and invisible enemy tactics #

In this first floor for a dungeon I ran, I used the various Duergar variants from Mordenkainen's Tome of Foes. The specifics aren't too important, however the key point I want to emphasise is that they do not leave their base defenseless. They have a mind master who should have some, even if it's elementary... level of magic capabilities, and they can situate watch-guards. So with these they can set up traps and a noisy watch-guard to announce when intruders have come.

Once intruders have come, all enemies that can be invisible, and be invisible for a reasonable amount of time do so. Their tactics here would be to wait and prey on any players who are alone. The DM can throw whatever might make their players split up... a few routing choices, loot that interests some but not all players etc. Once the player is split up, firstly these invisible enemies should lock the room where possible, then attack their enemy. With 5e rules they should have both surprise so they get a free round of combat, and unseen attacker so they have advantage on their attacks. For other TTRPG systems, consult how stealth attacks are handled.

For the Duergar, they then have stealth. They should also have enlarged where possible and surrounded the enemy, or at least cornered them(on account of their low movement speed). Additionally due to their rather unremarkable wisdom and intelligence scores, if other players attack they should not have very good alternative tactics so it will descends into chaos. When their leader dies or most of their friends die they lose morale and should try fleeing as they are intelligent enough to value their lives. Regarding their tactic for fleeing, If you want to run it intelligently, they should run and block their way out to buy themselves as much time to run on account of their low movement speed.

Traps #

The Boulder staircase #

The setup for this trap is a door that if opened without speaking the keyphrase(I would argue it should be easy enough to detect so I would use a magic glyph of warding here, but you can reasonably make it a mechanical trap if you want). Behind this door and this downward staircase, a wall opens revealing a 90,000 lb boulder. The weight is important as 90,000lb is roughly a 10ft diameter stone boulder, and this will also negate cheeky use of magic immovable rods. Ahead down this stairwell, are two illusory pit traps. The first one is a plain floor that has an illusion to make it look like a spike trap. The second one is a trap that is a real pit trap with an illusion over it to make it look like a plain floor. The idea here is that the first pit delays them and the second pit they need to jump when things are looking dicey. This second pit also serves as the end point of the boulder and the end of this trap.

Naturally anyone who falls down the real pit trap is crushed shortly after by that 90,000lb tombstone.

I also ran this with barrels at the top of these staircases that could on a 3 or 4 of a D4 be filled with gunpowder. I did not run these to explode, however tricksy delvers could've used them to destroy the boulder, caving the roof in preventing it from rolling forward or particularly evil Dungeon Masters could have them explode when the boulder collides with them. While the boulder hit these barrels, I elected not to have anything happen due to a lack of sparking. You could still reasonably say they exploded from the friction if you wanted though, and if the players wanted to make them detonate for the boulders I would allow it.

The alarm snare #

A fairly basic trap for a treasury. The door would have a glyph of warding with 3 spells it triggers. The first is alarm to wake up any denizens nearby. The second is ensnare to rope anyone in front of the door and hoist them up to the roof. The third is mold earth to turn the floor beneath them into stone spikes.

Now they have three options presented to them. Get out of the trap hastily and be impaled. Get out of it slowly and have friends defend them if they didn't get caught too, or get out of it slowly and then have all the denizens there and pelting them with all sorts of unhappy things.

Mold earth "force cage" #

Another basic trap, but more of a demoralisation trap. You have a bunch a glyph of warding with alarm and mold earth, that makes something matching the exact description of a force cage and describe the trap as being like the force cage. Now unless they are knowledgeable in the Mold Earth spell and would recognise it as such, they will be by meta gaming, demoralised. Mind you, I think Force Cage is a pretty rough and mean spell though. Naturally this door also has alarm on it. I personally do not think I ran this trap that well, but you might have better luck.

Conclusion #

This concludes the first part of Morgrim's indefatigable line of phylactery defenses.

Send all complaints of failed traps to "1, Dungeon of almost certain Doom and Misery, City of Yendor, M1S-3RY".

Published on 2026/02/07