Review of Sources
Volo’s Guide to the Sword Coast is the most significant source of information on this tower. Along of course with the Baldur’s Gate video game (and specifically its expansion Tales of the Sword Coast), though the 3rd edition campaign setting does briefly mention it.
Update: After writing this, I learned that the Adventurers League adventures DDAL05-08: Durlag’s Tower and DDAL05-09: Durlag’s Tomb also run through the tower. These 5th edition adventures are for parties of level 11 to 16. They relate to the Storm Kings Thunder storyline. If you are looking to run through the tower, then these adventures could be helpful for planning out encounters even if you don’t intend to run through it as written.
Background
This was once the keep of Durlag Trollkiller, son of Bolbur, a dwarven hero known for killing several dragons single-handedly. His adventures had allowed him to amass a large amount of treasure, and he chose this site as a place to hold it. He had hoped this would lead to the creation of a dwarven community here.
Magical wards and mechanical traps keep out most intruders well enough. But that hasn’t stopped many adventurers from trying, generally unsuccessfully. Over the years various creatures have been said to hold the tower, including fiends, will o’wisps, a dragon, and even mind flayers. In fact, it is the latter of these, along with their doppelganger allies, that eventually took the tower from Durlag and killed him.
The tower, however, is said to use these creatures for its own wishes in an attempt to protect the treasure it holds within though the creatures are not made aware of this.
As the 3rd edition campaign setting tells us, the slew of magic treasure about the place means that if you try to cast Detect Magic it will leave you dizzy.
What Makes it Unique Compared to Other Locations?
Manageable Dungeon Crawl
This is a large enough dungeon crawl that a party could be entertained by this over the course of many sessions. But it’s also not the Undermountain in Waterdeep. It’s filled with enough deadly traps to keep things interesting.
It’s Not Known What Lurks Within
It’s said that the halflings of Gullykin tend to understand at any time who is in control of the tower. But because there is no Forgotten Realms history regarding who controls it, at least for the last 120 years, there really is no guidance here over what could now control the tower. Especially since the Bhaalspawn likely cleared it out.
Secret Passageways and Prison Chambers
This place was designed to defeat anything that attempted to attack it. That includes having secret passageways that would let its forces move about it covertly. It also includes prison chambers, presumably created by Durlag for interrogating whatever fool decided to attack his tower.
Unique Traps and Spells
This dungeon is filled with ancient unique traps and spell wards. It’s said in fact to hold the deadliest traps ever seen in Faerun. The kind of traps that someone rich enough to build a massive keep in the middle of nowhere could put into it. This includes everything from wards to prevent invaders and looters from passing further into the keep, to shield portal traps, which are carved stone shields linked magically so that a dart, axe, or other missile weapon hurled into one would emerge from another, elsewhere in the tower. The shields themselves function as permanent wizard eyes or crystal balls, allowing an unseen watcher to observe from afar. If you can imagine a deadly trap in a dungeon, this place will likely have it. Nothing here is safe.
What are the Location’s Issues?
Filled with Traps
This is a place where even places within it that you think are safe could potentially still have active traps in them. These traps are well hidden, and even though who have visited the tower might not have seen traps that were only a few feet from them. One wrong step here could be the difference between a safe walk and a massive stone swing-hammer flying out towards you.
Hauntings
With various creatures dying here over the years the tower is known for being the source of hauntings. One apparition, in particular, is said to be seen regularly at the tower gates, a robed mage. It appears to observers that the mage is in some great fight for his life, though he quickly seems to succumb to a massive blow to himself delivered no doubt by some foul creature of the past.
Difficult to Get Deeper Into It
You need to have the correct ward stones to get anywhere further into it. How you want to handle this is up to you as a DM. The people of Gullykin have in the past been a good resource for groups looking to find these artifacts. Fake ward tokens can be found everywhere, however. Adventurers have been known to pay a thousand gold a month to rent the ones that are said to be legitimate. Though given the travel time to get to the tower, this seems unlikely.
How Can I Use It in My Campaign?
Obviously on paper Durlag’s Tower is a dungeon crawl. But there isn’t anything stopping it from becoming something more than this in the 130 years since it was likely cleared by the Bhaalspawn and their party.
The mind flayers have in the past expressed interest in the site. With its traps having been dealt with, it could have become a mind flayer colony.
There isn’t anything to say however that the traps can’t reset themselves here. Durlag had hired mages when designing the various wards here, and having the traps become reset seems well within the power of someone who could build a place like this.
At the same time, it could have become a dwarven colony as well. There is a lack of dwarven settlements in the area. This was also one of the intentions that Durlag had for the place. Maybe at least part of a colony now lives in it, and they are looking for adventurers to help clear out the rest of the dungeon so that they can expand.