This is part of a series! Go here to see the other entries.
Pit fiends are the lords, barons, viziers and generals of the Nine Hells. In other words, its upper management, just below the VPs (the archdevils) and the CEO (Asmodeus). As such, they’re both on the Monster Manual and on the Vault.
Each of the archdevils commands no more than a dozen or so pit fiends, each of whom fulfills an important role in the workings of that layer, commanding a whole army of lesser devils. The impression I get is that the Lords of the Nine are much more concerned with internecine political struggles than with actually running the business, so most of those diabolical schemes the PCs find themselves fighting are actually hatched by pit fiends and carried out by those lesser devils under them.
Pit fiends don’t usually get involved in the schemes they manage. They only show up in person when a big scheme is about to succeed… or when a band of plucky adventurers is about to seriously mess it up. When they do show up, they bring not only their own considerable power to bear, but also a number of backup plans and dirty tricks. Your typical pit fiend has Int 22, making it much smarter than its demonic counterpart, the Balor.
We’ll take a look at each version of the pit fiend separately, as there are some significant differences between them. In both cases they’re Large Immortal Humanoids (devils), and Level 26 Elite Soldiers (Leaders) with 486 HP.
Pit Fiend (Monster Manual)
The Monster Manual pit fiend has darkvision, Fire Resistance 30, and Poison Resistance 15. It fast as, well, a bat out of hell, running and flying at speed 12 (the latter with clumsy maneuverability). It can also teleport 10 squares at will.
The fiend projects auras of fear and fire out to 5 squares. Both affect only enemies caught inside, with the first inflicting a -2 penalty to all attacks and the other doing 15 fire damage per turn.
Its basic attack is a Reach 2 Flametouched Mace, which does both instant and ongoing fire damage. If you add both up, then you get a figure that’s actually appropriate for a monster of this level! The fiend can also attack with its Reach 2 tail sting, which does a bit less physical damage and allows a secondary attack against Fortitude for a bit more ongoing poison damage plus weakness (save ends both). As an elite monster, the pit fiend can use a standard action to attack both with the mace and with the tail sting at once.
Its “leaderly” ability is Tactical Teleport, which takes a standard action and recharges on 4-6. This teleports two allies up to 10 squares away from the fiend to any other square in that same radius. Instant flanking!
It has two minor actions. The first is the ability to create a Point of Terror in someone’s mind, a Ranged 5 attack that targets Will and inflicts a -5 penalty to all defenses for a turn. The second is the Irrestistible Command, which targets a lower level devil within 10 squares, slides it 5 squares, and causes it to explode and automatically deal some fire damage to everyone in a close burst 2.
Oh, and remember how fiends of all kinds in previous editions had the ability to summon others of their kind somewhat randomly? The MM pit fiend can still do that with a 100% chance success, once per encounter. The fiend can call up either 8 legion devil legionnaires, 2 war devils, or 4 legionnaires and 1 war devil. These are always explicitly an add-on to whatever encounter group the pit fiend is originally part of, and they’re not worth extra XP. While none of these are as individually powerful as the fiend itself, War Devils are strong enough to be concerning and the legionnaires make wonderful fodder for Irresistible Command.
Pit fiends start any fight they engage in by summoning reinforcements, because why wouldn’t they? They then use Tactical Teleport to set up some flanking situations, soften targets up with Point of Terror, and then charge into the fray to bash and sting fools to death.
The sample encounter is level 25: 1 Pit Fiend, 2 war devils, 2 astral stalkers, and 1 marut concordant. This doesn’t include the pit fiend’s summoned reinforcements! A harrowing boss battle for level a level 22 party, and the GM gets to come up with a fun reason for the marut and abominations to be working with devils. It’s not implausible, it just demands some backstory.
Pit Fiend (Monster Vault)
The Monster Vault pit fiend has exactly the same resistances, senses, and movement modes as the Monster Manual version. Its Aura of Fear is a bit different, marking all targets caught within it instead of giving them a general -2 penalty to attacks. The fire aura is the same.
The Flaming Mace attack is the first attack I see on a MV monster that has the exact same damage as it did on the MM! Clearly ongoing damage is supposed to be always be included in the average damage for the monster’s level. Makes sense, as it will almost always get applied at least once.
The tail sting has been simplified into a single attack that targets Fortitude, deals 25 ongoing poison damage and weakens (save ends both). The original only dealt 15, which was typical for epic monsters. 25 ongoing poison denotes a “blood of the Lernean Hydra” level of toxicity. The pit fiend remains able to make both a mace and a stinger attack as a single standard action.
The damage from the Irresistible Command explosion has increased a bit, and remains automatic. It also retains the use of Tactical Teleport, which remains identical.
The other big change here is that the summoning ability is gone. This is understandable, as it wreaks all sorts of havoc with 4e’s carefully tuned encounter design rules. In its place is Nightmarish Punishment, which triggers every time an enemy within 2 squares tries to shift or make an attack that doesn’t target the pit fiend. The fiend gets to make what amounts to a free mace attack against the target, only it slides them adjacent to the fiend instead of dealing ongoing fire damage. No escape!
I find it inevitable to compare pit fiends to balors, since both are technically the strongest creatures in their respective factions that don’t get individual names and backstories in the books.
If you look only at their individual stats, I think Balors feel scarier in personal combat. They have more HP, variable resistance, and their direct attacks do more damage. Still, pit fiends put up a respectable show in that department, and are much more capable of acting as a force multiplier for whatever other monsters are fighting with them. As with all devils, team composition is vital to make a combat encounter seem dangerous and scary. Even without the summoning ability, I’d encourage GMs to make pit fiend fights include a very large number of opponents, and have some of those appear by being summoned mid-fight.