The Monsters Know What They’re Doing

I’ve been procrastinating on analyzing the skull lord, because it’s another damn monster with a spellbook three inches thick. Spells are all right, but if you ask me, the way to make a monster interesting is to give it interesting features. A plethora of spells just creates analysis paralysis.

So what makes a skull lord different from a lich? Quite a lot, actually, but let’s start with the lore. Liches are megalomaniacal wizards who became undead in the pursuit of immortality and boundless power. Skull lords aren’t wizards but warlords—more correctly, agglomerations of warlords, former squabbling rivals now forced to share a single wasted body with three skinless heads.

Undead creatures are driven by compulsions, not survival instincts or rational motives. To run one, you have to know what its compulsion is. Here, it seems, the lore indicates two compulsions: to conquer and . . . to bicker. We’re gonna have some fun with this one.

Looking at the skull lord’s abilities, its Dexterity and Constitution are very high, more so than its strength. These are equaled by its Intelligence, but they’re surpassed by its extraordinary Charisma, which is also its spellcasting ability. This is an unusual contour: a combination spellslinger/skirmisher. It’s going to upend most of the principles we usually follow, in several ways:

• With its abundant spell slots, ample Constitution and immunity to a variety of debilitating conditions, this is the rare monster that wants to drag combat out. The baseline assumption of fifth-edition Dungeons and Dragons is that a typical combat encounter lasts three rounds, five at most. The skull lord, however, is content to take its time.
• Because Charisma is by far its highest ability stat, its preferred method of attack is spellcasting. However, if this were a player character, a Charisma-plus-Constitution contour would suggest a support spellcaster, like a bard, rather than a ranged spellslinger—one that stays close to its front line. This is consistent with the skull lord’s lack of a ranged weapon attack (although it does possess ranged spell attacks).
• Skirmishers need movement abilities to slip out of their enemies’ melee reach. The skull lord has three of these—haste, expeditious retreat and the legendary Move action—two of which conflict with each other, and one of which conflicts with another key ability.

But I’m getting ahead of myself. We’ve got some other features to look at. First of all, skills. Perception expertise (three heads are more numerous than one) plus Stealth proficiency equals excellence at ambush. The skull lord doesn’t necessarily strike me as a master of subtlety, generally speaking, but as a stalker summoned by an enemy to pursue your player characters’ party, it does possess the attributes of an effective hunter.

Resistant to physical damage from normal weapons, plus cold and necrotic damage, and immune to poison, the skull lord knows that it has to deal first with enemies wielding magic weapons or casting spells that do acid, fire, lightning, thunder, force, psychic or radiant damage.

It can’t be blinded, charmed or stunned, but it can be restrained or paralyzed. This is significant because, while the skull lord does have Legendary Resistance—three uses per day, as is customary—it can’t count on the battle’s being over quickly enough that it won’t need any more than those three. Most monsters with Legendary Resistance use it whenever they fail a saving throw, because they can count on a three-round encounter, and because they possess outstanding saving throw proficiencies—at least two of the big three. The skull lord doesn’t. In fact, it has no saving throw proficiency, just what it gets from its base stats. Thanks to Evasion, it also has effective resistance to any damage requiring a Dexterity save to avoid, but magic requiring a Con or Wisdom save poses a real threat. Thus, it has to save its uses of Legendary Resistance for the moments that matter most.

Above all, it will never allow itself to be paralyzed or restrained. Being undead, it also has a compulsion to avoid radiant damage, so it will use Legendary Resistance if it fails a save against that. Beyond those, it will use Legendary Resistance to avoid damage types that it lacks resistance to, but only if that damage comes from a spell cast at 5th level or higher, and only if the failed save isn’t a Dex save (which Evasion takes care of).

Master of the Grave confers advantage on undead allies of the skull lord when they’re within 30 feet of it. This gives it yet another reason to play the “support” position, a short distance behind the front line.

Oh, and let’s talk about those “undead allies.” The skull lord’s Summon Undead legendary action allows it to spam the battlefield with skeletons or zombies. Which to choose? Four times out of five, zombies. They’re dumber than skeletons, they’re less flexible, and their chance to hit is lower. But their Undead Fortitude keeps them on the battlefield longer, and attrition is at the heart of the skull lord’s strategy. The time to use skeletons rather than zombies is when the battlefield is spread out, enemy spellcasters are out of reach, and the skeletons’ ranged attacks are needed to pick them off.

That summoning ability is a beaut—which is why it costs all three of the legendary actions a skull lord has available each turn. Sure, an immediate counterattack with the bone staff or a cantrip is a nice retort to an impertinent attacker, but the real choice here is between Summon Undead and the Move legendary action, which equals a Disengage plus a Dash. The latter is key to making this quasi-skirmisher effective at skirmishing.

We’re almost there (glossing over the bone staff attack, which is a straightforward melee wallop that includes a tranche of necrotic damage), but the last part is the annoyingly complicated one: the spell repertoire. As usual, I’m following my practice of valuing spells by the number of slots available at their base level, meaning that only the skull lord’s 3rd- and 4th-level slots are available for boosting spells, and only 2nd- and 3rd-level spells will ever get boosted.

• Finger of death does an expected 46 points of necrotic damage (assuming a 50/50 chance of making the Con save) against a single target, with a potential maximum of 86 points. The Con save means it’s for the backline and buzzing flies, not for front-line fighters or supporters, and the amount of damage it deals, combined with the casting cost and the fact that it turns a corpse into a zombie, makes it less a first resort and more a finishing move against enemies who are already severely wounded.
• Eyebite requires concentration, which pits it against haste and expeditious retreat (see below).
• Cloudkill has the same benefit for the skull lord that it does for the lich: because the skull lord is immune to all poison, it can cast the spell anywhere, without regard to whether it’s in the area of effect itself. It has the drawback of requiring concentration. The radius is only 20 feet, so the skull lord has to make sure at least four enemies are within it (see “Targets in Area of Effect,” Dungeon Master’s Guide, page 249). Against four enemies, cloudkill does an expected 68 points of poison damage—but that’s per turn. If said enemies can’t (or don’t) escape the poison cloud, it will do more than that.
• Cone of cold is a monster, but one that’s only justified if it can strike all the skull lord’s enemies, or at least six, whichever is less. It’s also less desirable if the skull lord has many allies on the field which will also get caught in the blast. Against six enemies, cone of cold does an expected 162 points of damage. Holy snowstorm, Batman!
• Dimension door is an escape hatch, nothing more.
• Ice storm does an expected 69 points of cold damage and reaches flying enemies. Suboptimal if there aren’t flying enemies, because its effect on terrain favors ranged attackers, who are more likely to be fighting the skull lord than aiding it.
• Fear requires concentration and seems to go against the whole idea of destroying one’s enemies. You don’t want them to run away. You want them to stay and let you kill them.
• Haste dramatically enhances the target’s action economy, and unless the skull lord is accompanied by an undead ally much stronger than a skeleton or zombie, it will choose to target itself. Requires concentration, which rules out a number of other spells in the skull lord’s repertoire, and takes the skull lord out of commission if its concentration is disrupted, but you can’t have high reward without high risk. The question is, if the skull lord is happy to drag combat out, does it need to rev itself up like this? Depends on whether the opposition is likely to cooperate with the attrition plan.
• Mirror image is cute, but we have to ask about the opportunity cost—that is, an action spent casting mirror image is an action not spent doing something else. That being said, it does have some potential to drag combat out.
• Scorching ray is the one spell, given my self-imposed rule about boosting spells, that can be cast at higher than its base level, so we have three options: cast at 2nd level for three rays (average 21 points of total damage if all hit), at 3rd level for four rays (average 28 points of damage) or at 4th level for five rays (average 35 points of damage). Not hugely impressive, and not as good as a Multiattack with the bone staff, but flexible, with a slightly better chance to hit.
• Magic missile is underpowered at the level of challenge we’re looking at. Even if you cast it at 4th level, it still does only as much damage as scorching ray cast at 2nd level. Granted, every missile is an automatic hit—unless the target casts shield, and what self-respecting mage doesn’t know shield? And the skull lord’s +10 spell attack hit bonus means the vast majority of its scorching rays will land. Magic missile is a desperation move at best; the skull lord will cast dimension door and vamoose before it ever has to cast magic missile.
• Expeditious retreat offers free movement (but not free disengagement) at the cost of the caster’s concentration. It enhances action economy, but not as well as haste does (albeit without the risk of exhaustion). A poor substitute for haste in situations where the skull lord’s opponents hit so hard and fast that the skull lord can’t drag the battle out the way it would like to. Better on a larger battlefield against more mobile opponents.
• Thunderwave is an alternative to the Disengage action that also packs a bit of additional ouch. Useful only when the skull lord is being double- or triple-teamed by melee attackers. Against two opponents, it does an expected 14 points of damage—be still, my beating heart. It could do as much as 54 points of expected damage, however, if we broke my rule and boosted it all the way up to 4th level. Let’s put a pin in that for the moment.
• Chill touch, fire bolt and ray of frost all do respectable ranged dink damage, because the skull lord is a 13th-level spellcaster. On a hit—and remember, +10 spell attack bonus—they do an average of 14, 16 and 14 points of necrotic, fire and cold damage. In addition, chill touch inhibits healing, while ray of frost slows the target. These are all inferior to a single bone staff hit, but they are ranged rather than melee attacks.
• Poison spray requires a Con save rather than an attack roll, with an average of 20 points of poison damage on a failure.
• Shocking grasp does only an average of 14 points of lightning damage on a hit, plus inhibiting reactions. This has exactly one use: allowing the skull lord to do a smidgen of damage, then retreat without risking an opportunity attack, thus sparing it from having to use the legendary Move action.
• Mage hand LOL.
  

All right, 2,000 words in, it’s finally time to put it all together. By a mile, the skull lord’s best opening play—if its enemies are appropriately clustered together—is cone of cold. In fact, cone of cold’s value decreases substantially the more allies the skull lord has on the field, and spamming the field with allies is going to be at the core of the skull lord’s strategy, so it wants to cast cone of cold as soon as it can. If the pieces just aren’t coming together for cone of cold, its next choice is probably to just march up to an enemy and whack him or her three times with its bone staff. (It’s saving ice storm in case it has to deal with flying enemies, and cloudkill until it has skeleton or zombie allies on the field, which also happen to be immune to poison.)

Then it’s going to watch carefully and note how its opponents react. If a melee opponent comes up to it and does significant damage—let’s say, at least 32 points of damage after resistances are applied—it’ll use its legendary Move action to back away from that opponent immediately, so that it doesn’t happen again, and it will repeat this action each time the same trigger occurs. Having already used Move at least once, it will use the last and (if applicable) second-to-last opponent’s turn before its own next turn to burn off its remaining legendary actions with bone staff or cantrip attacks.

On the other hand, if it gets all the way through its opponents’ turns without using the legendary Move action at all, it will use all three of its legendary actions to Summon Undead and bring a bunch of zombies or skellies onto the field. The first batch, if the skull lord isn’t already accompanied by allies, will form a front line in front of it, so that it can do its own thing unmolested by melee attackers. Otherwise, it will send them to harass pesky skirmishers and backliners.

Once its opponents are tied up fighting undead minions, that’s when the skull lord will let rip with cloudkill, so that now they face the ugly choice of either breathing toxic fumes or incurring opportunity attacks as they flee the poison cloud. Note that the skull lord has two 5th-level spell slots, so if it never gets around to casting cone of cold—if the proper circumstances never present themselves—it can play the cloudkill card twice.

After only a round or two, it will be clear to the skull lord which of its opponents it hates the most: some combination of wielding spells or a magic weapon, dealing radiant damage, and being generally good and pious. It’s going to direct the bulk of both its minions and its own attacks at this opponent. Once that opponent is reduced to 40 percent of its maximum hit points or fewer, it targets that opponent with finger of death.

Otherwise, its general approach is going to be to either move in and deliver bone staff attacks or hang back and lob scorching rays (although it still stays within 30 feet of its own front line). If it’s being bedeviled by melee attackers who are actually somewhat effective against it, it may take a turn to cast mirror image, but it knows better than to try that twice if its opponents are popping all its simulacra with Extra Attacks. In that case, it may cast haste to try to match its enemies’ pace. On its opponents’ turns, it uses the legendary Move action if it has to, Summon Undead if it can. If it’s at risk of running out of minions, it’s more likely to hang back, so that it doesn’t have to use up its legendary actions disengaging. If there are plenty of minions on the field, it’s more likely to make melee attacks.

Here’s a question: Does a skull lord have any self-preservation instinct? I’m not sure it does, given the nature of its compulsions and the manner of its creation. However, suppose it’s created by some other being in order to do its dirty work. That’s an investment. That other being doesn’t want the skull lord to throw its undeath away. In this instance, and only in this instance, the skull lord will cast dimension door (using a 4th-level slot if it still has one, or else that not-especially-useful 6th-level spell slot—the one that belongs to eyebite, which the skull lord probably isn’t going to cast) and try to kill its foes again sometime later. Otherwise, it fights until it’s destroyed.

That covers the compulsion to conquer. What about the compulsion to bicker? This is where you, the dungeon master, can have some fun. The bickering isn’t necessarily going to alter the skull lord’s tactics, but it can flavor the tactics. Give each of the three heads a personality—for instance, the “General,” the “Warlock” and the “Sneak.” Whenever it uses the legendary Move action, the General accuses the Sneak of being a coward. When it attacks with its bone staff, the Warlock demands to know why the General is engaging in such dull brutality instead of casting spells, while the Sneak berates the General for exposing itself to attack. When it casts spells, the General says it’s bored and wants to hit something. When it uses Evasion to reduce damage on a Dex save, the Sneak pointedly says, “You’re welcome.” The slapstick comedy of the skull lord’s internal dissension will contrast memorably with the serious-as-a-heart-attack damage it dishes out and the seemingly innumerable minions it summons from the earth.

Next: treants.