We now return to two of our more cinematic undead creatures: ghosts and mummies. Aside from being horror-film staples, they don’t have a lot in common with each other, except for one thing: each is bound to a specific location. A ghost has “unfinished business” and haunts an area closely related to whatever trauma it needs to resolve; it’s compelled by the urge to resolve this trauma. A mummy is the guardian of a tomb or other burial place, compelled to punish transgressors against either the tomb itself or, sometimes, the person buried there. (In the latter case, the mummy may leave the tomb to hunt down the transgressor. In the former, it always stays put.)
Ghosts may be malicious, but they don’t have to be. (A malicious ghost that for some reason is permanently prevented from resolving the trauma connected with its death may end up as a poltergeist instead.) They may want to punish people who wronged them in their previous lives, but they may also be sorrowful, lonely, lost or even deceiving themselves that they’re still alive. Revenge against those who wronged them might satisfy them, but so might making amends to those whom they wronged. You really can’t have a decent ghost without a backstory.
Ghosts are immune to the same debilitating conditions as specters and wraiths and mostly resist the same types of damage (the exceptions are silvered weapons, which don’t bother them, and cold damage, to which they’re entirely immune). They also possess darkvision and Incorporeal Movement. This is where the similarities end, however. Ghosts don’t Drain Life, nor do they have Sunlight Sensitivity (they prefer the dark, but they aren’t harmed by the light), nor are they driven to kill every living being they encounter. They have a different toolkit and a much different sort of compulsion: the resolution of their death traumas.
Possession allows a ghost to take control of a target humanoid. A ghost will possess a player character in order to perform physical actions that it can’t perform in its incorporeal state (such as opening a door or a container or retrieving an object), to talk to people to whom it doesn’t want to reveal itself as a ghost, to move outside the place it haunts, and so forth. A lawful good or neutral good ghost will even ask for a PC’s permission before possessing him or her. A chaotic evil ghost, on the other hand, will not only possess a PC against his or her will but may even relish making him or her do humiliating things. Regardless, the ghost always possesses people specifically to bring about the resolution of its trauma, although the connection between the trauma and the possession may not be direct or obvious. While a ghost could possess a PC and force him or her to attack other party members, it generally won’t bother to do so, because more often than not, it can do more damage on its own with Withering Touch.
Withering Touch does an unpleasant amount of direct necrotic damage, and that’s it. In general, even if an encounter with a ghost goes south, the ghost won’t attack everybody in the party—only the PC(s) who attack it or who actively interfere with the resolution of its trauma. A ghost uses Withering Touch primarily for deterrence and self-defense, not with intent to kill (unless that’s part of the resolution of its trauma). If one or more PCs fights back with magical weapons or does radiant damage to a ghost, it will back off right quick, Disengaging (action) and retreating at full movement speed in a straight line away from the party, through any creatures, objects or physical barriers in the way. A ghost can’t resolve its trauma if it lets itself be destroyed, so its self-preservation instinct is much stronger than those of most undead creatures. Similarly, if a ghost is repelled by Turn Undead, unlike most undead, it will keep its distance from the PC who turned it. Anyone who isn’t going to help a ghost resolve its trauma is no longer relevant to its interests.
Horrifying Visage causes targets to be frightened and, if they fail their saving throws by 5 points or more, to age 1d4 × 10 years on the spot. Again, whether and when a ghost uses this feature depends first and foremost on the nature of its trauma and what’s necessary to resolve it. A compulsion to keep people away from a certain place is one reason why a ghost might use it. To haunt a person who wronged the ghost in its previous life is another. Ghosts will also use Horrifying Visage against those who offend or upset them, and they don’t have complete control over their use of it, so even good ghosts that lose their cool may bust out with a Horrifying Visage, although they’ll be remorseful and apologetic about it afterward. (Evil ones won’t feel a lick of regret.) A ghost won’t use this feature round after round, because there’s no good reason to do so: characters affected by it will have run away, and characters unaffected by it will be immune to it for the next 24 hours anyway. But if it’s upset or offended again, it may do so anyway, involuntarily, even though it won’t have any further effect.
In short, ghosts aren’t interested in combat unless it involves killing someone they’re compelled to take revenge against. They’ll fight back with Withering Touch to defend themselves, but as soon as it’s no longer necessary—or they’re hit with damage that truly hurts them, or turned—they’re done. (Incidentally, as a DM, I wouldn’t award experience points for “defeating” a ghost that the PCs merely drive away. I would, however, award full experience points to PCs who resolve a ghost’s trauma and thereby release it without destroying it.)
Mummies are compelled by obedience to the will of their (nearly always evil) creators. They’re brutes, with high Strength and Constitution but low Dexterity. They also receive a bonus on Wisdom saving throws, which makes them strong against two of the “big three” saving throw abilities. They’re resistant to physical damage from nonmagical weapons and immune to necrotic and poison damage but vulnerable to fire. They have darkvision (pretty important, if your full-time job is guarding a tomb) and are immune to several debilitating conditions.
Rarely, a mummy may be sent out into the world to pursue the targets of a curse laid by its creator, but most of their time, they stand guard inside a tomb to punish would-be robbers or desecraters. Once a PC enters a part of the tomb that’s off limits, or opens a coffer or coffin that he or she oughtn’t, the mummy arises and attacks. Unless it’s attacked back, it targets only the transgressing PC. Its movement is slow (20 feet) but relentless. On its turn, it advances toward its target (move), then Attacks if it can (action). Beyond melee range, this attack consists of a Dreadful Glare; since success means the target flees and failure means the Glare has failed to elicit suitable Dread, it will use this feature only once per transgressor. Within melee range, the attack consists of a Dreadful Glare if the mummy hasn’t already used this feature on the target, followed by a Rotting Fist. (The latter may be an opportunity attack if Dreadful Glare caused the target to flee; otherwise, it’s used alone, or it’s just the second part of the mummy’s Multiattack.) Once the mummy has closed with its target, it keeps pummeling him or her with Rotting Fist until the character falls unconscious or the mummy is destroyed . . . or . . .
Fire! Mummies are driven by compulsion (Intelligence 6), but they do have a sense of self-preservation (Wisdom 10), albeit a weak one. Fire pits the one against the other. If attacked with fire in melee, they’ll Disengage (action) and retreat 20 feet (move), but they won’t flee, because they still have the same compulsion to defend their burial place against transgressors. Instead, they remain in a standoff, waiting for the source of fire to go away so that they can attack again. If attacked with fire at range (a thrown Molotov cocktail or fire-based spell), they’ll direct a Dreadful Glare (action) at the source of the damage. If the attack fails, they’ll retreat 20 feet (move); if it succeeds, however, they’ll go right back to what they were doing before. If a full round goes by without their taking any more fire damage, they’ll also go back to what they were doing before. Mummies are extremely mechanical in their behavior: you might expect an area-effect fire spell such as burning hands or fireball to scramble their circuits, but aside from avoiding the source of the damage and trying to make it go away, they never deviate from their orders. Using Turn Undead against a mummy doesn’t deter it in the slightest: as soon as it wears off, the mummy returns to the slow-motion chase.
A mummy lord is another matter entirely—so powerful and complicated that I’m going to save it for tomorrow.