The premise of this blog is that evolved creatures know how to use the abilities they were born with. The interesting thing about undead creatures, in this context, is that they’re not evolved creatures—at least, not anymore. The transformation to undead status doesn’t entirely erase what a ghost or zombie was in its previous life, nor does it necessarily come with a set of survival rules that any and every undead creature will adopt. Undeath is a curse, and as such, it creates what I think of as compulsions. That is, whatever spell, influence or event caused a creature to rise from the dead also drives that creature to behave in ways that have nothing to do with its own self-preservation. In fact, since the creature has already experienced death, the concept of “survival” is essentially meaningless to that creature. Consequently, how badly an undead creature is injured has nothing to do with whether it will flee, and the tactics it uses will have less to do with how to effectively guarantee its continued existence and more to do with the particular compulsion that drives it.
Two types of undead that player characters will encounter often at low levels are skeletons and zombies. Both are (usually) former humanoids, raised from death through necromancy to act as minions without free will or personality. Their compulsion is obedience to the orders of their controller, which usually involves killing interlopers. When idle, a skeleton will revert to habitual behaviors from its former life (the Monster Manual offers, as an example, the skeleton of a former miner miming digging with a pick), while a zombie will just stand around. Both are literal in their interpretations of instructions and lack independent problem-solving ability, though skeletons have an easier time circumventing obvious obstacles. And both will fight until they’re destroyed, regardless of the amount or kind of damage they’ve taken or the strength of the opposition.
How a skeleton fights will depend on how it would have fought in its previous life. A former archer, for instance, will instinctively know to maintain a certain range from its targets (40 to 80 feet, if possible). A former duelist will occasionally use the Dodge action to avoid incoming blows from multiple targets or the Disengage action to relocate to more favorable ground. Most of the time, though, skeletons are former guards or other shlubs and will take a simple, direct approach to melee fighting: engage, swing sword, repeat. That being said, a skeleton ordered to guard a room, for instance, will break off combat with any opponent who leaves that room. It won’t pursue, and it may even forgo an opportunity attack against an opponent who’s obviously leaving the scene, because it’s accomplished what it was ordered to do. Skeletons are vulnerable to bludgeoning damage, but they’re not independently reflective enough to avoid a PC with a mace. Skeletons will retrieve dropped weapons, open doors, avoid hazards and approach their targets by the easiest path.
Zombies retain no vestige of their former selves. They approach their targets by the most direct path, even if this means marching straight through an environmental hazard. They won’t pick up a dropped weapon (and if they’re not carrying one in the first place, they never will, unless their controller orders them to). They might break through a closed door, but they won’t ever think to unlatch it. And they’ll pursue their targets until either those targets are dead or their controller orders them to break off.
D&D zombies aren’t like TV zombies: they don’t eat their victims, and they don’t turn their victims into new zombies. But you don’t need to tell your players that! Their one unique feature, Undead Fortitude, makes them frighteningly relentless (one way to emphasize it is to have them fall prone when damage would otherwise reduce them to 0 hp, then immediately get back up). Beyond that, whatever the players believe about zombies—whether they’re right or wrong—will make the experience of fighting them that much more thrilling. Because, honestly, any thrill that comes from fighting zombies won’t come from their dazzling tactical skill. Zombie encounters are as likely to result in comedy as excitement, as when, for example, a rogue with Expertise in Acrobatics entices a zombie into pursuing her out a third-story window. As the DM, you absolutely should reward your players when they come up with ways to exploit zombies’ fundamental design flaw.
An interesting low-level undead creature that’s not used nearly as often as it deserves is the shadow. Great for horror campaigns, subterranean dungeons and other creepy settings, the shadow’s compulsion is to siphon the vitality from living beings, especially ones who are pure of heart. Shadows avoid light, particularly direct sunlight (it gives them disadvantage on everything); running into open sun is the only sure way to escape from a shadow. Its other features are Amorphous (it can pass through the crack under a door) and Shadow Stealth (Hide as a bonus action in dim light or darkness), and it has not only a high Stealth proficiency but resistance to all sorts of damage, including damage from normal weapons, and outright immunity to most debilitating conditions. Its sole weakness is radiant damage, so not only is your good cleric or paladin its juiciest victim, he or she is also the one who’s best equipped to defeat it. That’s fair.
Its Stealth proficiency and Shadow Stealth feature together define the shadow’s tactics. First, it lies in wait for a victim. When one appears, it uses its movement and its bonus action to approach with Stealth to within reach of the target, then Hide. If the Hide bonus action is successful, then it Attacks the same round, with advantage, using Strength Drain (action). If the Hide action is not successful, it keeps moving, to try again next round. The beauty of this tactic is that, even if a PC spots the shadow, the DM can say, “You saw a shadow move past you,” and the fact that the shadow is a creature may not even occur to the players at first. All they’ll know for sure is that something is there.
Once the shadow attacks successfully, it no longer has the ability to Hide until it moves out of view again (unless the PCs are foolish enough to be stumbling around in total darkness without darkvision), and this is where its compulsion comes into play: once it latches on to a PC, it will keep draining that PC’s strength, even though slipping away for another surprise attack might be more effective. What has the power to make a shadow think twice about what it’s doing? Probably nothing but radiant damage, being struck by a magical weapon, or a cleric or paladin’s Turn Undead feature. If one of these is used against it, it will Disengage (action), move out of view, Hide (bonus action) and wait for its victim to come within striking distance again.
Strength Drain can be nasty, not so much because of the average 9 hp of necrotic damage it does with each hit but because of the 1d4 it reduces its target’s Strength by each time it hits. The ability points are gone, potentially affecting the PC’s attack and damage rolls and ability to use certain weapons and armor, until the player completes a short or long rest—and if the PC’s Strength is reduced to 0, he or she dies on the spot. The PC doesn’t simply fall unconscious. The PC dies. Skeletons and zombies have long since lost any ability they may have had to frighten players, but an encounter with a shadow should terrify them. I encourage DMs not to overlook this monster.
Next: ghouls and ghasts.