D&D 5e: Kaiju Battle as a Complex Trap 2


As you know if you’ve been following my work for long enough, I’ve spent a lot of time working on how to handle kaiju battles in D&D 5e. To spell that out a bit: I want something that uses the PCs’ combat abilities and mostly feels like a fight, but the enemy is beyond their ability to kill – their goal is to evade it, drive it back momentarily, or accomplish other goals. My first effort here was converting Rite Publishing’s Kaiju Codex from Pathfinder to 5e, which you can and should still buy.

For obvious reasons of not wanting to plagiarize… myself, I’ve been looking for new and different ways to handle kaiju for Under the Seas of Vodari. That effort led to Dokahi’s Brood: Rhaluq the Many, which has some cool ideas but still makes a monster that is too fragile for late tier-3 PCs, compared to the intended encounter design.

In this post, I want to explore the possibilities of using the Complex Trap rules in Xanathar’s Guide to Everything as a scaffolding for Rhaluq the Many. I’m setting it as a Tier 3 challenge, sort of arbitrarily – in real UtSoV usage, you’d probably customize the scaling to the PCs’ current tier, with a story justification that it is still weakened by slumber if you need to run this in Tier 1 or 2. Stealing something from under the body of a kaiju sounds like an amazing Tier 1 or 2 adventure to me.

Rhaluq the Many

Complex trap (level 11-16, deadly threat)

Rhaluq the Many is the newest form of an immortal and apparently indestructible horror. It has changed names and forms countless times, as heroes rise to destroy or contain it.

Trigger. Rhaluq the Many stirs from its magical slumber when a creature with a Dexterity (Stealth) check result of 15 or lower comes within 120 feet, a creature with a Dexterity (Stealth) check result of 20 or lower comes within 60 feet, or when a creature with a Dexterity (Stealth) check result of 25 or lower comes within 30 feet. Rhaluq awakens immediately if it takes damage.

Initiative. Rhaluq acts on initiative count 20 and initiative count 10.

Active Elements. Rhaluq’s vast, crab-like form, and all of the humanoids that it is made from, lash out in a storm of wrath.

Movement (initiative count 20). Rhaluq moves 30 feet toward the greatest concentration of creatures within 1 mile.

Psychic Invitation (initiative count 20, refresh 5-6). All creatures within 60 feet of Rhaluq, and visible creatures within 120 feet, make a DC 20 Charisma saving throw. A creature that fails this saving throw must use its reaction to move its speed toward Rhaluq. This effect activates as often as it is available.

Slam (initiative count 20 and 10). Rhaluq makes a melee attack against each creature in a 40-foot cone with a +8 bonus to the attack roll, dealing 33 (6d10) bludgeoning damage on a hit. The cone area that it attacks on initiative count 10 can’t be the same as the area it attacked on initiative count 20.

Psychic Chorus (initiative count 10). The countless tormented minds of Rhaluq the Many lash out. Roll 1d4 and consult the following table.

1 – Rhaluq projects an illusion that the water within 120 feet of it turns to slime. Each creature in the area must make a DC 20 Intelligence saving throw. On a failure, its speed is reduced to 5 feet until the end of its next turn.

2 – Rhaluq fills the area with psychic static. Each creature within 120 feet of it must make a DC 20 Intelligence saving throw. On a failure, it suffers 22 (4d10) psychic damage, and has disadvantage on Constitution saving throws to maintain concentration on spells until the start of its next turn. On a success, it takes half damage and no further effect.

3 – One creature of Rhaluq’s choice within 120 feet must make a DC 20 Wisdom saving throw, becoming blinded, deafened, and disoriented for 1 minute on a failure. A disoriented creature that moves on its turn moves in a straight line and a random direction (roll 1d8). At the end of each of the target’s turns, it can make a DC 20 Wisdom saving throw, ending its conditions and its disorientation on a success. A lesser restoration also ends the disorientation.

4 – Unconscious or dead creatures within 40 feet of Rhaluq roll a death saving throw. On a failure, the creature merges with Rhaluq. A dispel magic, remove curse, or dispel evil and good spell cast with a spell slot of 5th level or higher releases one merged creature that the caster names as part of casting the spell. The creature is alive with 1 hit point, in a space within 5 feet of Rhaluq. If Rhaluq does, each body separates and can be raised or resurrected individually.

Dynamic Elements. The psychic storm of Rhaluq the Many grows as creatures continue to resist it.

Increased Potency. The damage dealt by Slam and the damaging effect of Psychic Chorus increases by 11 (2d10) psychic damage each round after it activates, to a maximum of 33 (6d10) psychic damage.

Scramble Teleportation. A creature that attempts to teleport while within 120 feet of Rhaluq must make a DC 20 saving throw, using its spellcasting ability score. On a failure, the creature instead teleports to a space within 5 feet of Rhaluq. If a single spell or effect teleports multiple creatures, the creature that casts the spell or uses the effect rolls the saving throw, and all of their targets are affected according to their result.

Countermeasures. There are a few ways that Rhaluq can be escaped or driven back. Rhaluq is immune to all conditions.

Song of the Deep Dreamers. The songs of the College of Deep Dreamers soothe creatures such as Rhaluq. A creature that is within 120 feet of Rhaluq that knows the proper song can make a DC 20 Charisma (Performance) or Charisma (musical instrument) check. On a success, Rhaluq gains one level of slumber. Charisma checks after the first successful check in each round have disadvantage. When Rhaluq has 6 levels of slumber, it deactivates.

A bard that is not a bard of the College of Deep Dreamers can recall the proper song with a DC 20 Intelligence (Arcana) check. A non-bard can make the same check with disadvantage.

Flee. When there are no creatures within 150 feet of Rhaluq on initiative count 0, it rolls 1d6. On a roll of 1-3, Rhaluq gains one level of slumber. When Rhaluq has 6 levels of slumber, it deactivates.

Massive Damage. When Rhaluq takes 75 or more damage from a single damage source, it doesn’t move on its next initiative count 20, it has disadvantage on attack rolls until the end of the attacker’s next turn, and the DC of all saving throws for its effects is reduced by 5 until the end of the attacker’s next turn. Rhaluq has a +7 bonus to all saving throws it rolls and is immune to poison and psychic damage.

Killing Rhaluq. It is generally impractical to kill Rhaluq with normal force, as it has 10,000 hit points and regains 100 hit points at the end of each minute. Volcanic eruptions or other natural disasters typically only slow it down for a time.

Design Notes

Let’s find out what questions I’ve forgotten to answer in attempting to present a creature as a trap! (I’m nervous about this one – please be gentle.) If I can get it into working shape, with the aid of my cherished readers, I’ll try a similar model for the other three Deep Dreamers of the Seas of Vodari setting.


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2 thoughts on “D&D 5e: Kaiju Battle as a Complex Trap

  • Craig W Cormier

    I really like this as an encounter/adventure idea. I get that you are using the Complex Trap rules as a guideline, but I don’t think this is actually a “trap”, which to me is something that surprises the PC (even if the players expect it), but that is picking awfully small nits.

    In the context of this particular encounter, it might be helpful to define exactly what you mean by “creature”, especially for the Movement and Flee abilities. Like does a school of tuna count as the largest concentration of creatures within 1 mile? Or is Rhaluq specifically interested in sentient beings? Do the sea slugs and crabs that are scurrying to get out of Rhaluq’s way count as creatures for the Flee mechanic? Oceans are full of things that qualify as creatures by the common definition. I assume Rhaluq will swim if the closest concentration of creatures is above it somewhere, despite its description as crab-like.

    You may wish to add a way of determining random vertical movement to the 3rd option of Psychic Chorus since this is intended to be an underwater encounter.

    Overall, I think this is a really cool idea and would love to see you expand it to include the other Vodari kaiju and the tarrasque.

    • Brandes Stoddard Post author

      The format only uses “trap” in the subhead because I need to be clear about the rules mode to use – otherwise, no, not a trap at all. =)

      I haven’t made up my mind about whether Rhaluq pursues every living creature or just sentients, but I have an easy time believing that a Deep Dreamer/kaiju would devastate all living things in a region, until every mobile animal fled a distance of more than a mile – or that the bards and others who keep the Deep Dreamers asleep would take steps to turn aside or kill every living thing that approached within a mile of one of them. There are, after all, only four in the setting, and they have the whole ocean to work with.

      Good point about 3d movement.

      Glad you like it!