Release the kraken! A high-level boss monster that player characters won’t encounter until they’re masters of the realm (if you, as their dungeon master, have a shred of decency in you), the kraken isn’t so much a creature as it is a natural disaster.
Running a kraken, like running a dragon, requires keeping track of legendary actions and lair actions as well as regular and bonus actions and reactions. One consolation is that, of all boss monsters, the kraken is probably the most likely to be encountered outside its lair, unless the PCs are on a mission to slay it. On the other hand, if the kraken is encountered within six miles of said lair, its regional effects mean that PCs will have to run a gantlet of hostile crocodiles; swarming schools of quippers; giant crabs, frogs, seahorses; sharks of all kinds; and water elementals. They’ll also have to contend with torrential rain and storm-strength winds, imposing disadvantage on navigation checks, Wisdom (Perception) checks that rely on sight or hearing, and ranged weapon attacks. In colder climes, they’ll have to make DC 10 Constitution checks against exhaustion every hour—and saving throws every minute if they fall in the frigid waters—unless they have natural or magical protection.
In its lair or out of it, the kraken is a juggernaut, with only average Dexterity but godlike Strength, Constitution and mental abilities. No, it’s not just a mindless engine of devastation. It’s smarter than anyone in your adventuring party and most likely wiser as well, and its massiveness and majesty are mesmerizing. Its decisions in combat should convey a sense of calculated malice and cruelty. It knows everyone’s weaknesses, and it doesn’t miss an opportunity to exploit them. If it chooses to communicate (via telepathy), it will be only to taunt, belittle and humiliate its victims; there’s nothing a kraken wants that the PCs can tempt it with.
A kraken has proficiency on every kind of saving throw except Charisma, so spellcasters don’t impress it—unless they try to cast divine word. That spell will get its attention, and not in a good way. But for divine word to have an effect, the target has to have 50 hp or fewer. The kraken starts with 472. Let’s stipulate right now that if a kraken encountered outside its lair is seriously injured (reduced to 188 hp or fewer), it flees back to its lair, forcing its foes to fight it on its own turf if they want to finish it off.
A kraken is immune to lightning damage and to being frightened, paralyzed or magically restrained. It’s immune to physical damage from nonmagical weapons. It has an armor class of 18. It’s fearless, and opportunity attacks concern it not at all. Its Siege Monster feature doubles the damage it does to inanimate objects and structures. If you show up in a ship, it’s not going to attack you—it’s going to attack the ship, then deal with you when you’re floating in the water, making saving throws against hypothermia.
On its own turn, the kraken has three choices of Attack action: a triple Multiattack comprising three tentacle or Fling attacks; a single bite attack; or a single Lightning Storm.
- Tentacle is a bludgeoning attack with a 30-foot reach that automatically grapples on a hit. A grappled target is restrained, giving it disadvantage on attacks and giving the kraken advantage on attacks against it.
- Fling can be used only on an enemy who’s already grappled. The MM says the enemy is thrown “in a random direction,” but I’d overrule this. The kraken has Intelligence 22. It’s not going to Fling anyone or anything in a random direction. It’s going to aim. If there’s another enemy within 60 feet who’s annoying the kraken, it will Fling its victim at that enemy, potentially doing bludgeoning damage to that enemy and knocking him or her prone as well (and remember, the kraken has advantage on attacks against a prone enemy it’s within 5 feet of). If there’s no one the kraken particularly wants to throw its victim at, it will Fling the victim as far as it can, at a solid surface—and as any diver will tell you, water is a solid surface if you don’t enter it properly. I’d suggest requiring an opponent Flung into the water to make a DC 18 Dexterity (Acrobatics) saving throw to pull into a dive and enter the water without taking damage. Also, there’s nothing that says the kraken has to Fling an opponent it’s holding grappled. It can keep making tentacle attacks against that opponent, squeezing it or smacking it against things, and it does so with advantage, because the opponent is restrained. Whether a kraken Flings an opponent or keeps it grappled depends on the likelihood that the opponent will struggle free. An opponent with an Acrobatics or Athletics skill modifier of +3 or lower is fairly unlikely to escape, so the kraken may as well hold on. It’s got 10 tentacles; it’s not likely to run out of them.
- Bite can be used on a grappled or ungrappled opponent. Against an ungrappled opponent, it simply does damage. But a grappled opponent, on a hit, is swallowed. A swallowed opponent is blinded, has no movement and has disadvantage on attacks against the kraken from inside. He or she is also subjected to acid damage from the kraken’s digestive juices every round. This is a good way to take a troublesome opponent out of play, especially one likely to break the kraken’s grapple.
- Lightning Storm can strike up to three targets at once—or a single target three times! The Dexterity saving throw DC is huge, and the attack does damage even if the target succeeds. This is the kraken’s nuclear option for dealing with a low–hit point, high–damage output enemy such as a wizard or sorcerer, but it’s also a highly effective way of striking enemies it can’t reach with its tentacles.
As a DM whose players have risen to level 11 or higher, you should have a good idea who in the party is most dangerous, who’s most durable and who’s most fragile, and the loss of whom is most likely to demoralize the party. The kraken knows everything you know. It can “read” the PCs’ abilities as if it had their character sheets in front of it, and it can calculate their threat level as if it were referring to “Creating a Combat Encounter” in the Dungeon Master’s Guide. It can also sense immediately whether any of them has a weapon capable of harming it. It uses this information to choose its actions:
- If, as previously mentioned, the PCs are on a ship, or some other floating whatsit that’s keeping them dry, the kraken attacks it first, attempting to destroy or at least capsize it. Contrary to what you might expect, it does this with Lightning Storm, not with tentacle attacks, because it does more damage (both mean and maximum) and because inanimate objects can’t make Dexterity saving throws, so the hits are automatic. However, if the PCs’ vessels are Large or smaller—say, if they’re in rowboats or kayaks—the kraken will strike them with its tentacles, and if they’re not destroyed outright, it will seize them and Fling them. A PC who’s “knocked prone” owing to his or her boat’s being Flung should be considered to have fallen overboard.
- If the PCs are unsupported by some other structure, either in the water or on land, the kraken’s threat assessment comes into play. At first, when it’s undamaged or only lightly wounded (having 331 hp or more) and if the encounter is rated Deadly for the PCs, it contemptuously attacks the weakest and most vulnerable targets first. If the three most vulnerable are all more than 30 feet away, and its movement won’t allow it to close the distance in order to reach them, it strikes them with Lightning Storm. Otherwise, it strikes with its tentacles. Its No. 1 target is the PC most likely to make the other players go, “Nooooooooo!”
Note that a kraken doesn’t have to attack three different targets, nor does it have to wait until its second turn to Fling, squeeze or bludgeon a grappled target. It can seize one target with a tentacle as its first attack, Fling that target as its second and grab another target as its third. Or it can seize two, then Fling one. (What it can’t do, though, is grab an opponent and swallow him or her in the same turn.) Its goal is to do as much damage as it can to each one; if it grabs one who’s got a good chance of struggling free (Acrobatics or Athletics modifier +4 or higher), it either tries immediately to bash him or her unconscious (if he or she has 52 hp or fewer) or grabs, bashes, then Flings him or her at another opponent between 30 and 60 feet away.
- Once the kraken is moderately wounded (reduced to 330 hp or fewer), or if the encounter is rated Easy, Medium or Hard for the PCs, it takes its opposition more seriously, and it focuses its attacks not on the most vulnerable but on the most dangerous. Again, it uses Lightning Storm if its biggest threats are out of tentacle reach; otherwise, it attacks with its tentacles. It doesn’t Fling an opponent it considers especially dangerous unless that opponent has a good chance of struggling free (Acrobatics or Athletics modifier +4 or higher), but it also doesn’t try to swallow any opponent who might be able to do 50 hp or more damage in a single turn from inside it. Any such opponent, it simply holds onto with its tentacle and keeps squeezing or bashing until it no longer needs to.
- At some point, it’s possible that the kraken will have grappled every opponent within reach whom it considers a major threat. If this has proved effective—if it’s neutralized their ability to do any meaningful harm to it—it will keep grabbing up its other opponents, until it runs out of either opponents or tentacles. (The former is more likely.) It then moves to get the ones who’ve been out of reach so far. If it can’t get at them with its tentacles, it strikes at them with Lightning Storm.
The kraken also has legendary actions, taken at the end of other creatures’ turns. These comprise a single tentacle or Fling attack, a Lightning Storm attack (which costs two legendary actions) and Ink Cloud (which costs three). Ink Cloud can be used only underwater; the kraken uses it as a defensive measure as soon as it’s moderately wounded (reduced to 330 hp or fewer), anytime all its opponents are within a 60-foot radius around it, and once more when it’s seriously wounded (reduced to 188 hp or fewer) and about to retreat. At the end of the turn of any opponent who tries to attack it in melee, it makes a legendary tentacle attack against that opponent. If it hasn’t yet had a chance to Fling an opponent it probably won’t be able to hold onto, it does so at the end of the turn just before that opponent’s. If enough PCs’ turns have gone by that it’s obviously not going to need to make more tentacle or Fling attacks before its own turn, and it still has two or more legendary actions left, it uses Lightning Storm. Otherwise, it uses any legendary action left over before its own turn on a gratuitous tentacle attack.
In its own underwater lair, the kraken has a choice of three lair actions, always taken on initiative count 20:
- A strong current pushes opponents away from the kraken.
- Lightning damage is doubled against creatures within 60 feet for one round.
- The water itself does lightning damage to creatures within 120 feet.
Per the wording of the lair action descriptions in the MM, the effects of the second and third lair actions can’t be stacked: Either lightning damage is doubled, or the water does lightning damage, but never both. But also note that, unlike chromatic dragons or mummy lords, the kraken is not restricted from using the same lair action two turns in a row. Thus, lair action No. 3 is the default. Anytime the kraken doesn’t plan specifically to use lair action No. 1 or No. 2, it uses No. 3.
Lair action No. 1 pushes creatures out of the kraken’s reach—but most of the time, the kraken wants its opponents within reach, so it can grab them. This lair action is appropriate only under specific, limited circumstances: either the kraken is seriously wounded; or it’s got hold of a dangerous opponent whom it doesn’t want to let go of, and another opponent within 30 feet, who’ll be hard for the kraken to grab or keep hold of, is trying to help him or her get free.
The kraken’s Lightning Storm ability reaches out to 120 feet, but its second lair action doubles lightning damage only within 60 feet. Since the kraken generally prefers to attack enemies within reach with its tentacles rather than Lightning Storm (grappling them restrains them and confers advantage on attacks, along with the option to devour), lair action No. 2 is appropriate when the kraken plans to use Lightning Storm against opponents who are between 30 and 60 feet away from it.
A kraken out of its lair is playing offense; a kraken in its lair is playing defense. If the PCs have enough chutzpah to confront a kraken in its own lair, it has to take them seriously from the get-go, and it won’t mess around abusing vulnerable opponents for the fun of it. It will go straight for the most powerful of its enemies and do its level best to disable or debilitate them. Its primary goal is to neutralize; killing, as an end in itself, is secondary.
A kraken staring death in the face in its own lair is in a terrible bind: it wants to flee to save itself, but it’s also stronger inside its lair than outside it. It really doesn’t want to leave its lair, nor does it want to die. Thus, it has to consider what means of defending itself will be most effective against its attackers. If they’re more agile than they are tough, an Ink Cloud does poison damage to every enemy in a 60-foot radius (that’s 60 feet from the center of the kraken—all its other abilities are measured from its physical exterior), gives them disadvantage on all their attacks by heavily obscuring the area, and makes the kraken untargetable by spells. If they’re tougher than they are agile, Lightning Storm does guaranteed damage, albeit to only three enemies at a time—but lair action No. 2 can double that damage. If it doesn’t have confidence in either of these recourses, it will use lair action No. 3 (if its enemies are all badly injured) or lair action No. 1 (if not) one last time before either Disengaging (if it’s within reach of a melee attacker) or Dashing (if not) and swimming away at full speed.