So far, I’ve steered clear of what fifth-edition Dungeons and Dragons categories as “fiends,” and now it’s finally time to dive in. Most fiends fall into one of three groups, depending on their alignments: Devils, belonging to the infernal hierarchy of the Nine Hells, are lawful evil. Demons, inhabitants of the tumultuous Abyss, are chaotic evil. And yugoloths, whose name comes from a Slavic phrase meaning “southern loths,” are what AD&D referred to as “daemons”: neutral evil fiends from the gray waste of Hades. Or Gehenna. Or the “Blood Rift.” Or all the evil Outer Planes. The publishers of D&D can’t seem to make up their minds.
I’ll begin with devils, the embodiment of tyranny and ruthlessness. The driving motivation of a devil is to dominate. In the hierarchy of the Nine Hells, authority is absolute, rules are binding, and obedience is imperative—but within those rules, every devil seeks to maximize its advantage, elevate its position and increase its power over others. Every devil’s bargain looks fair, but no devil will ever accept an agreement that is fair. Agreements between devils, or between a devil and another creature, always contain exploitable loopholes that a devil can use to ensnare the sap foolish enough to accept its terms.
Generally speaking, devils stick to the Nine Hells and their own infernal rat race. Devils encountered on the material plane where the player characters live their lives are there for one of two reasons: either they’ve been summoned magically by some idiot who thinks he or she can benefit from dealing with them, or they’re working to advance the interests of a higher-level devil.
Because of this, PCs probably won’t encounter the lowest-level devil, the lemure, anywhere except in the Nine Hells, so I’ll skip past that one and move directly on to the lesser devils, the ones that PCs are most likely to encounter.
Imps are errand runners, information gatherers and mischief makers. PCs will most likely encounter them while they’re acting as intermediaries between a greater devil or archdevil in the Nine Hells and a mortal spellcaster or agent of an infernal cause. With low Strength, high Constitution and very high Dexterity, they fight as skirmishers, using flight, invisibility and stealth to zip in and out of combat. They can Shapechange into various beast forms, of which the most advantageous is the raven, which has the same base movement speed but a faster flying speed than the imp in its true form.
Imps, like every other devil we’re going to look at today, have 120 feet of darkvision and Devil’s Sight, suggesting a strong preference for going about their business at night and underground. They also have resistance to unsilvered normal weapons, cold damage and magical effects, and are immune to fire damage and poison. Thus, despite their few hit points, they can afford to close with an enemy to deliver a poisonous sting or bite.
However, an imp dares not let itself be diverted from its assigned task. If combat with a group of PCs would prevent it from fulfilling its duty, it’s going to prioritize escape over attack, and its most effective way of escaping is simply to turn invisible and fly off. Imps are suited for only the most menial guard duty, but a group of them might be ordered to watch a spot and dive-bomb anyone who trespasses there. In that case, they’ll assume their diabolical raven form and perch 30 feet up in the air, concealing themselves with Stealth; when trespassers arrive, they’ll fly down, attack their targets and fly back up out of reach. This means possibly incurring one or more opportunity attacks with each strike, but because of their resistance to damage from normal weapons, they’re not too worried about this. An imp ordered to guard a location will not flee.
Spined devils are also messengers and spies. With high Dexterity, average Strength and only slightly above average Constitution, they prefer sniping over melee engagement and will therefore favor the use of their tail spines. So that they don’t have disadvantage when attacking, they’ll maintain a range of 40 feet (preferably aerial), fly in to a distance of 20 feet, fling a pair of spines, then fly away again. If an opponent closes to melee distance, a spined devil will retreat 20 feet, attack with its tail spines again, then retreat another 20 feet.
Only when they’ve run out of tail spines (each one has 12) will they use their bite/fork attack, and they do this the same way that imps do: fly down, attack, fly up. The difference is that spined devils have the Flyby feature, which lets them avoid any incoming opportunity attack as they swoop back up. But like the imp, a spined devil won’t fight at all if that isn’t what it was ordered to do; instead, it will fly away as fast as it can. Also like the imp, if it was ordered to fight, it won’t retreat, no matter how badly wounded it is.
The bearded devil is a diabolical warrior. With high physical attributes across the board but no ability to fly, and wielding a polearm with a 10-foot reach, it closes to melee distance and engages fearlessly. This devil is content to remain at a distance of 10 feet and attack with its glaive alone, which inflicts “infernal wounds” that cause a target to bleed hit points on subsequent rounds; at this distance, opponents with normal-reach weapons won’t be able to fight back. If an opponent chooses to close to within 5 feet, then the bearded devil uses its Multiattack, striking with both its glaive and (LOL) its beard. Note that while a target is beard-poisoned, it can’t regain hit points even by magical means, but magical healing can still cause an internal wound to stop bleeding out. Bearded devils fight to the death and never retreat.
Barbed devils are soldiers and bodyguards. They have very high physical attributes across the board but can’t fly, and their melee Multiattack (claw/claw/tail) does slightly more damage than their ranged Multiattack (Hurl Flame × 2) and is also slightly likelier to hit. Therefore, they’ll generally prefer melee engagement over ranged attacks, using the latter only against ranged attackers striking them with magical weapons or ammunition, or spellcasters casting combat spells that either require Dexterity saving throws to avoid or inflict elemental damage other than cold, fire or poison (e.g., acid). They’re not sophisticated fighters, but they do have the sense to determine who their most dangerous enemies are and focus those down, rather than waste time on opponents who can’t do much (or anything) to hurt them.
Chain devils are jailers and torturers. They’re brutes, with exceptionally high Strength and Constitution and no ability to fly, but their chains have a 10-foot reach, so rather than stroll right up to their opponents, they’ll close only to within 10 feet before attacking.
Their Animate Chains feature is intriguing and requires careful reading to grasp. This feature doesn’t animate the chains that a devil is holding and using as weapons. Rather, it imagines chains lying around wherever the devil happens to be (a prison or torture chamber, probably), which the devil then brings to life to fight as its allies. These chains do the same damage as the devil’s chain weapon and can also hold enemies restrained, causing them damage and granting the devil advantage on attacks against them. There’s no duration limit on this ability, and it adds so much to the chain devil’s action economy that we have to assume it uses this ability right away at the start of combat, even though it can’t take any other action that turn.
The chain devil can make reasonable guesses as to which opponents pose the greatest threat, and it will focus both its grappling attempts and melee attacks on these. Although the text doesn’t make it entirely clear, the devil wields more than one chain, so it can continue to flog a target grappled with one chain using another chain; it simply can’t use the chain in one hand to grapple a second target when one is already grappled by the chain in the other. Animated chains, on the other hand, can grapple one additional target apiece. So figure that the chain devil itself uses the chain in one hand to strike and grapple what it believes to be its most powerful enemy, uses the chain in the other hand to continue beating it, and uses its animated chains to seize the enemies it believes to be next-most powerful.
As for its Unnerving Mask feature, this is a reaction, usable against only one opponent per round. I figure that devils probably have a pretty good sense for foolishness in mortals, so the chain devil can judge accurately which of its nearby enemies is most likely to flub a Wisdom saving throw.
It should go without saying at this point that chain devils don’t retreat, even when seriously injured.
Bone devils are infernal middle management, overseers of lesser devils and damned souls. Their physical ability profile marks them as brutes, but their Dexterity isn’t far behind their Strength and Constitution. They also have no ranged attack. However, they can fly. Based on these facts, I conclude that the bone devil will fight hovering in the air, just because it can, at a range of 10 feet from its chosen target(s), so an opponent who can’t reach a height of 10 to 15 feet with his or her weapon will be unable to fight back. Like barbed devils, bone devils can judge accurately who their most threatening enemies are and will prefer to attack them. And like all the devils above, they’ll never abandon their duty by retreating.
Is the polearm variant any better than the standard variant? Against AC 15, a +8 attack modifier means a 70 percent chance to hit. A claw/claw/sting multiattack can therefore be expected to do 33 hp of damage per turn (setting aside the Constitution save against being poisoned, which is equal between variants). The polearm Multiattack grants only one use of the weapon, but the weapon also does two dice’s worth of damage, for the exact same amount of expected damage. The polearm grapples a target but doesn’t restrain it, so there’s no advantage on attacks against that target, nor does the target attack with disadvantage. The bone devil is also restricted, at that point, from using its polearm on any other target. On the other hand, the target can’t get away. Overall, I’d say it’s a wash, imposing a minor loss of flexibility on both sides which favors the side with the greater numbers.
There’s another variant rule on page 68 of the Monster Manual, “Devil Summoning,” which allows certain devils to summon assistance. Among the lesser devils, barbed, bearded and bone devils have this ability. They have to give up one turn’s action to do this, and there’s no guarantee that they’ll succeed.
In the case of barbed and bearded devils, this action summons another devil of the same kind, essentially doubling the power of the original devil. However, their chance of success is only 30 percent. Should they bother? It depends on how much they gain from the one round of attack actions they give up. D&D 5E assumes that the average combat encounter lasts three rounds. Based on this, a devil that uses its first turn to summon an ally gives up one action and has a 30 percent chance of gaining it back, plus one more—a net expected loss of four-tenths of an action. On the other hand, in an encounter in which the devil isn’t favored to win, doubling the number of devils should nearly double the length of the combat. Suppose bringing in a second devil turns a three-round encounter into a five-round encounter. Now the devil gives up one action and has a 30 percent chance of gaining it back, plus three more, a net expected gain of two-tenths of an action.
To me, this isn’t worth the likelihood of failure. Instead, for these two types of devils, I think summoning an ally is the last-ditch tactic of a devil that suspects it’s about to die. Consequently, they’ll use this action when they’re seriously injured (reduced to 44 hp or fewer for a barbed devil, 20 or fewer for a bearded devil), provided they’re not able to finish off their opponents in a single attack themselves.
A bone devil, on the other hand, has a 40 percent chance of summoning 2d6 spined devils or another bone devil. Forty percent, as opposed to 30 percent, makes the summoning of an equal-strength ally a better deal: now going from three rounds of combat to five means giving up one action but gaining 1.6, a net expected gain of six-tenths of an action, which could actually amount to something. But never mind that, because a 40 percent chance of summoning, on average, seven flying devil porcupines is absolutely worth it. Each of them, flinging its tail spines, can deal an expected 8 hp of damage per turn against AC 15. Seven of those equals 56 hp of damage per turn, significantly better than a single bone devil can do. Now, instead of a 40 percent chance of gaining four actions for the cost of one, we’re looking at a 40 percent chance of gaining 6.8 actions for the cost of one, a net expected gain of 1.7 actions. In other words, attempting to summon 2d6 spined devils is at least as good as getting an extra full round of bone devil actions, very likely two. That’s a no-brainer. Do it in round 1.
Next: greater devils.