If you’re looking for evil forces that you’re able to throw onto your players for the nextDungeons & Dragonscampaign, few things say ‘evil’ more than demons. Inhabitants of the Abyss, these fiends are a perfect opportunity for a classic good vs. evil story, with legions of monsters terrifying the world or a particular powerful Demon Lord trying to get into the material plane through followers and whatnot.
How can you implement them, though? From official lore to encounters and gameplay, you may do plenty here. And, in case you’re using a homebrew world, nothing stops you from analyzing and adapting them as you see fit to your scenario.
7Learn The Demon’s Basic Information
Baphomet via Wizards of the Coast
As mentioned, the Abyss is where demons come from, divided into many layers but ultimately governed by pure chaos.Demons are chaotic evil,after all, so making people suffer is their main pleasure, and having a demon BBEG who just wants to get out and kill people for sport is in character for them, as vague as it is.
They can help people, such as becoming patrons to Warlock-like figures or fighting alongside them in battle, but usually, that’ll happen because said people are helping the demon achieve their goal. And the demons would likely ditch them once they served their usefulness, so whenever you’re roleplaying a demon, think of the worst thing you could do and go for it.
6Respect The Demonic Lore
The Abyss is vast and has many creatures fighting for supremacy, with the strongest ones becoming Demon Lords - many of those are even considered Deities, such as Lolth, Goddess of the Drow. Mortals can also become Demon Lords by conquering part of the Abbys, which opens the opportunity of picking evil people from a player’s backstory and leveling them up to BBEG status, or maybe even tempt the more neutral or evil players into corruptive power.
Another important part of their lore is the Blood War, which proves that demons' greatest enemies are not angels, as one would expect. Instead, their biggest foes are Devils, who are also evil but with a more structured organization, so if you intend to add Demons as a big part of your story, consider adding Devils too, and letting players take advantage of their animosity toward one another to get rid of both sides.
5Use Them At Any Level
If you’re going for a long campaign of evil-smiting, demons are a perfect choice, as there are demons to fight against from level one to 20. Demons have a fantastic variety in terms of power, with their Challenge Rating going from 1/4 to more than 20.
Thus, you can create an ongoing narrative of a Demonic invasion right at the first session and maybe even have your Demon Lord show up at the beginning - not for a fight, obviously, as it would destroy your players, but to set the stage and put some fear in your players' hearts. And you get an excellent structured narrative out of it, which is very satisfying to your players and, let’s face it, to yourself for pulling it off.
4Embrace Their Numbers
Now, just because you have some true behemoths among the Demons, that doesn’t mean you should ignore its weaker monsters after your players are no longer level one, and even a powerful foe can be obliterated by a party thanks tothe action economy. Only you using your action, bonus action, and reaction against four (or more) people doing the same will likely not go well for you, and you can take advantage of the many types of Demons and their variety in stats and abilities to mix them up.
Has your party finally defeated a CR three Demon that you’ve used as a boss? Now that they’re stronger, you can start using multiple versions of this same boss as minions for future encounters. It’ll raise the stakes, but at the same time, give your players the advantage of knowing the enemy and the satisfaction of seeing how much stronger they are now by handling multiple of what was once a Boss encounter for them.
3Understand The Demon Behavior
As mentioned before, demons lack a structured hierarchy, so how will a mighty BBEG demon have an army, then? It’s simple: Sheer brute force. This opens up many opportunities to roleplay pure terror throughout the campaign since a BBEG Demon will show cruelty and strength over their minions just as much as they’d show their enemies.
Don’t tolerate failure even if it means brutally attacking weaker Demons for shock value, and since they’ve got no rules they can do dark stuff like targeting beloved NPCs, bargaining their freedom, and decide not to fulfill their end of the bargain. As a bonus tip, we’d recommend talking to your players about how violent these creatures can be and if they’re okay with it.
2Pay Attention To The Demon’s Weaknesses
To kill a demon, they must be slain in their home plane (aka the Abyss), otherwise, they will re-materialize there rather than die. This is also perfect for an endgame mission with theplayers entering the Abyssto kill a Demon Lord since they have to be killed there to die for good, or you could also keep their essence in a special amulet that will make them immortal until said amulet is destroyed, making matters more difficult.
As far as actual weaknesses go, Demons don’t have a lot of those since they’re resistant to a lot of things and rarely present any vulnerability. However, your biggest concern here is probably Banishment, since Demons are from a different plane and if you’re banished then your Demon will be banished for good, or until they leave the Abyss like they did the first time.
Sure, let your players succeed with their Banishment, but if this is a trick they do every time, it’s best to start countering it. A Legendary Resistance, a high Charisma saving throw, or minions who can attack the spellcaster and break their concentration are good ways of dealing with that.
1Creating Your Demon
In case you want to make your monster, we’d recommend weak ones to be small, while the rest be at least large. Chaotic Evil is a must-have alignment here, along with a few resistances, and perhaps even non-magical weapons in general, just to make your martial’s lives more difficult (keep in mind how difficult you want the fight to be, though). They have unique features, so we’d recommend going through them, seeing which ones fit your creature, and adapting them to it.
As for a Demon Lord, you can just go to town since their CR is above 20, so feel free to put a lot of power there, with great damage, abilities that cause conditions such as frighten or paralyze, innate spellcasting, and ensure they’ll be good at Charisma saving throws to avoid being banished. To roleplay your creation, just be a terrible person, and you’re good to go - unless you want your character to behave differently from the norm.
