Dragon Encounters

The glabrezu is an extremely powerful demon, powerful enough that I have no idea why its CR is only 9. It has Darkness and truesight, by itself a potent enough combination that would render it a lethal threat. Add to that grappling, [admittedly without the restrained effect that sometimes accompanies grappling] with a range of 10 feet, enough to render most melee units helpless to attack [the exception being if their weapons have reach.]

To complete this picture, it has a level 8 spell, the ability to cast spells and make melee attack on the same turn, and while its AC and HP aren’t extremely strong, they’re not especially weak either. Its high intelligence, willingness to negotiate, and stockpile of treasure mentioned in the flavor text are icing on the cake.

I would seriously suggest that you raise this monster’s CR to 13, or at least to 11.

How to Use

According to the flavor text, the glabrezu delights in allying with people in order to corrupt and destroy them. (Keith Ammann has an entire list of how the glabrezu might use talking to destroy people [I especially like his cursed item idea], but I don’t see most players falling for them. Read his ideas here.)

There are two major problems here. The first is that the players will know better than to trust a demon, and with the calm head that comes from it not being real life, together with the fact that as a DM you have to give them a fair way to win, they’re not going to follow a demon. The second is that you cannot destroy a player character from within. To do so would require completely rewriting his/her personality, and if there is anything in D&D that you should not do, it’s that.

Overcoming the first problem requires hiding the fact that it’s a demon. I’ll discuss ideas for doing so below. The second idea is fairly insurmountable. I will discuss ideas for how the glabrezu can corrupt or betray the PCs, which is perhaps somewhat close, but to destroy them internally is impossible. Keith Ammann’s approach is fun to read, and would work well in a book, but I just don’t see any way to do it in a game. (Except his cursed item idea. That one I really like.)

Bad Influence Part 1: Deception

If you’re using this approach, when they meet the glabrezu it will insist that it doesn’t want to fight. It will tell them, if they’ll listen long enough to give it a chance, of how blowing up an Abyss portal scattered the magic of the portal and ended up transforming it into this shape. It might not even fight back for the first round of their attack, in the hopes of convincing them.

(If you’re using my idea about the chaos being visible in a demon’s eyes, it will admit that the magic is filling it with an urge to murder, to kill, but it will claim to be holding the urge in check. It can even say that it’s going to kill itself to protect the world, or ask them to kill it if they see that it’s going out of control. It just has one thing it needs to do before it can die.) Once they believe it a little, it can ask them to help it with one quest, which is chosen to corrupt them or otherwise bring them down.

 Whatever you do, don’t show them the glabrezu’s picture in the Monster Manual, as then they’ll know that it’s an actual monster.

If you want to increase its chances of convincing them, let the first time they meet it be in the darkness. It created this darkness, but they won’t know that. Instead, prepare a precipice for them to stumble over, or a net trap that will fall on them and catch them. Then the glabrezu will help them back up after they fall onto the ledge, or help them out of the net, or if it sees them hesitating to go further it can warn them about the precipice or the net. (It will say that it didn’t know they were there until it heard them talking. They don’t know that it has truesight, and it has no reason to tell them.)

When it reaches for them, they will feel the claw, but it will be less alarming when that’s all of it that they feel. Also, the fact that it’s helping them will vouch for the glabrezu’s good intentions. Before they go out of the darkness, it will feed them the above story about being transformed, so that when they see it they were already braced for it.

Perhaps an even better method of convincing them would be for it to show up in the middle of a battle. Perhaps it feels that it has done enough with its previous masters and will now use their deaths to make new “Friends.” If it has a summoning ability [the summoning variant] it can send its summoned demon[s] to attack the PCs and then show up a round or two later to help the PCs in battle. Ideally, use both the cultists and the summoned demon[s] together.

The players won’t be able to question it in the middle of combat, and by the end of combat they’ll have at least some reason to trust it. Whether it can convince them after that is up to you and them.

If they allow it to join them, there is no reason for them to know all its abilities. I would give them two of its at-will spells, and one or two of its once per day spells. I would tell them that it can either make two attacks with its pincers, or cast one spell with its hands a turn. Finally, I wouldn’t tell them about its truesight or its resistances and immunities, and I definitely wouldn’t tell them about its summoning ability, if using the optional summoning variant.

Which spells to tell them about? Power Word Stun seems a pretty logical spell to leave back, being an extremely useful ace in the hole. Regarding its at will spells, you obviously can’t reveal that it has Darkness if it uses it to meet them. If you didn’t use Darkness, you might as well let them know about it. They’ll find it useful, thus motivating them to trust the glabrezu, and Dispel Magic isn’t a bad spell to hold back. I’d think revealing Detect Magic would be to the glabrezu’s advantage, as he’ll want to use it to figure out what he can about the PCs capabilities, and not having to worry about them realizing he cast it is a benefit.

If they let the glabrezu accompany them, his main goal is to steer them into a corrupting path, but since that is so hard to pull off in a D&D game you might have him steer them into a dangerous path instead. As a DM, you can’t dump a fight that’s too difficult on them, but you can let them wander into the middle of a dangerous area and have to find a way out with difficulty.

Ideas for corruption and betrayal will appear in the next article. [This one got too long.]

The Glabrezu’s Combat Style

The main spells the Glabrezu is going to use are Darkness and Power Word Stun. Darkness is so incredibly powerful that about the only reason not to cast it on any given round is if it’s already up, or if he knows that a PC is able to dispel it and he wants to use his turn to take out that PC.

Power Word Stun is its ace, for taking out an especially frustrating enemy. If a PC has the ability to dispel Darkness, and does not have proficiency is CON saving throws, he is definitely the target. (Can the glabrezu tell which saving throws a PC has? I would say that sometimes it can. Is seems fairly obvious that a barbarian or fighter has CON save proficiency. Other times it’s less obvious, such as if the PC is a sorcerer, or if the source is a magical spell or item. If the glabrezu traveled with them, presumably that would improve its chances of knowing.)

Dispel Magic is extremely situational. If the glabrezu sees a spell that would be worth dispelling, and has even a 50% chance of dispelling it, I would say it should go for it. Its fists don’t do all that much damage anyway.

The other three spells require concentration, and so are almost never worth casting at the expense of Darkness [with a possible exception in the case of Confusion, but only if it can maximize its use. See below.]

It will use Detect Magic when not engaged in combat, to fish for information. In fact, when the PCs meet it, Detect Magic is probably active.

Confusion can be worth it if it can get the majority of its enemies together, which it might be able to thanks to its grappling ability. [I only realized this as I was writing it. Great, another way in which it’s overpowered.) Even if its enemies are already grappled, it might be worth casting as this frees up its pincers to go after other enemies. I guess the question is how often is Darkness getting dispelled or rendered irrelevant due to area-of-effect spells, how likely are its enemies to make their WIS saves, and will casting it take out almost all its enemies? If the answer to two of the three questions favors using Confusion, do so.

I have no idea when it would use Fly. I guess for traveling, although this won’t show up much in the campaign. When pretending to be friendly, it can also offer to cast this on one of the PCs. If they accept, you’ll know that they’ve been completely hoodwinked. (The person casting Fly can cancel it at any time. If the target is five miles up, that’s just too bad for him.)

How to Use Darkness? Well, in addition to permanent disadvantage to the PCs and permanent advantage against any PCs inside its radius, by standing inside it the PC’s will have trouble knowing where to aim their ranged weapons [perhaps have them tell you its trajectory, if using a battlemap. Don’t forget to have them roll an attack roll so that they don’t know whether they hit or missed. With theater-of-mind, I suggested in the basilisk encounter that getting the right area has a 50% chance, aside from the chance of rolling to hit (which still has disadvantage.)] Play it as you feel best.

The PCs can’t see through Darkness to the other side, not just they can’t see what’s in it. One possible strategy for the glabrezu would be to grapple to melee fighters, so it can hold them out 10 feet away, where they can’t hit it, and then stand behind [on the far side of] the darkness. This means the area-of-effect spells will hopefully not hit it, if they assume the glabrezu is inside the darkness, and will hit the melee fighters. They’re also being kept in the dark so they don’t realize, and warn the other PCs, that the glabrezu is behind the darkness.

In addition, by keeping the prisoners in front of him, I’d say the glabrezu should be considered as being behind at least partial cover. (Arguably, there should also be a chance for ranged attacks to hit the prisoners instead. Especially as the darkness means they can’t see where they’re aiming However, D&D doesn’t have a friendly fire rule, so you’d have to homebrew it. Also, if might cause friction at your table.)

The other strategy, for when your players have realized that they should target the area behind the darkness, is for the glabrezu to capture whichever two PCs have the fewest HP, and stand inside the darkness holding them on either side of it, so that area of effect spells hit them as well. If it has the spellcasters captive, then when the melee PCs come after them it might get them all into a small area and target the entire party with Confusion.

Combat Encounters

This is the part of every article where I suggest terrains and traps to make every monster into an absolute menace. As it happens, the glabrezu is already there before I did anything. I thought we’d start this section by looking at what areas don’t favor the glabrezu, and what he’ll do when fighting in them. (Answer: He’ll crush the players. Anyway. Bad terrain isn’t nearly enough to make him lose.)

• (difficulty 12) A Wide-Open Area: I already covered everything here in how to use Darkness, above. This is the textbook case discussed there.
• (difficulty 11) A Narrow Hallway: The negative for the glabrezu is that it can’t get out of the way of their ranged attacks, and it can’t hide from melee fighters with Darkness (they’ll still get disadvantage, but they will know where it is.) On the other hand, a narrow area is optimal for Confusion.
• (difficulty 13) A meeting of four passageways into an X junction [a four-way] junction, is the most ideal of mundane [non-trap] situations. It will cast Darkness in the middle, and they have no idea which of the four options it chose. Nor is there any way to target more than one of them with an area-of-effect spell. Finally, when they find it, they’ll probably cram into the passageway it’s in to get past its Darkness, which will let it cast Confusion. [Regardless of the length of each passageway, the glabrezu will stand near the middle.]
• (difficulty 15-17) If you want the typical terrain for this blog, as in a situation that favors the glabrezu, use the fall in the middle of the room I mentioned above in Deception. (Half the room was a pit, with a ledge partway down that ran along the side of the pit.) To make it even harder, you can place multiple pits around the center of the room. For maximum difficulty, place concealed pits. They won’t be able to see them even when there isn’t darkness, which means they won’t be able to memorize the locations. You can also use other traps, such as rolling boulders, falling nets, tripwires with or without crossbows, and anything else you want.