I'm currently designing a 5th edition campaign with an antagonist who's sorta like this sociopathic mix between Jafar and the Joker. He's always got some plan to escape unscathed and has tons of strings he can pull to get his way. That's because he's this summoner who can creates hoards of elemental-based monsters to do his bidding, and he's a master at what he does. Despite this though, he isn't much of a heavy hitter himself, instead he just sics his own minions on his enemies.

I want the fight with him to be one where the challenge comes from fighting the sheer numbers and power of the monsters he summons, rather than from his great strength as a spellcaster. Are there any monsters like this in D&D I can use as a reference?

I'm aiming for a party level to be 15, maybe a bit above if necessary, by the time the final encounter happens. As for the encounter itself, I'm hoping to make it just challenging enough to create a struggle, but not so challenging it might be considered "deadly".


Demons summon demons

See the "Variant: Demon Summoning" sidebar on MM. p. 54:


Summon Demon (1/day): the demon chooses what to summon and attempts a magical summoning. {A few examples cited here for brevity}

  • A marilith has a 50 percent chance of summoning 1d6 vrocks, 1d4 hezrous, 1d3 glabrezus, 1d2 nalfeshnees, or one marilith.
  • A nalfeshnee has a 50 percent chance of summoning 1d4 vrocks, 1d3 hezrous, 1d2 glabrezus, or one nalfeshnee.

For your party's level, a CR 16 marilith ought to make for an interesting fight.


If the marilith summons a lot of allies early in the fight, the fight turns from "CR appropriate" into "deadly and beyond" rather quickly as you add up the XP budget. That's very swingy. You seem to want a tunable encounter.

A more tunable encounter: glabrezu

Encounter budget hard for 4 x 15th level ~ 4300 x 4 = 17,200 XP worth of monster/NPC.

While it starts as a CR 9 fight, which is well below your party's threshold (5,000XP) look at who the glabrezu can bring to the party:

30% chance of summoning 1d3 vrocks, 1d2 hezrous, or one glabrezu.

Let's say your glabrezu summons another one, that's two 5,000 XP monsters, times 1.5 = 15,000. Heading toward the budget for hard at this point.

  • Does the second demon summon more help? Let the pace and tempo of the fight tell you when to pull that trigger. If the party is all over demon number 1, call for more help. If they start cold, wait before the second demon calls for help.

    Instead, summoning a few vrocks early to tune the fight to a difficulty to your liking may be a better pace for this party. Each vrock summoned is 2300 XP/CR 6.

    How does that add up? (A review of DMG pages 80-84 regarding how to deal with the XP budgeting for your party would help as you work through this.)

    The glabrezu summons 2 or 3 vrocks at the beginning, and you end up with your XP budget being 5,000 + 5,800 or + 8,900 multiplied by 1.5 or 2 as you see fit. As with the other answer, CR/XP math is inexact, particularly at high levels. 10,800 X 1.5 = 16,200 ; 10,800 X 2 = 21,600. The hard encounter is somewhere between those two numbers.

You are in the ball park for a hard to deadly encounter, and you don't have to roll the dice to see what the demon summons. You are the DM. Pick some demons to summon deliberately so that you can tune the encounter to your party.

Is this the only fight of the day?

Look at how many "adjusted" XP your party can handle, based on page 84 of the DMG. Adjusted XP per day per Character: 18,000. For a 4-person party, that's 72,000 XP worth of adjusted encounter monsters so let's go back to the marilith example.

The marilith summons another marilith.

16,000 + 16,000 X 1.5 ( two monsters) = 48,000. Within bounds, certainly.

Second marilith summons a glabrezu: (32,000 + 5,000) X 2 = 74,000. Almost dead on.

First marilith summons a glabrezu, who summons three vrocks: (16,000 + 5,000 + 8,900) X 2 = 59,800. Manageable.

First marilith Summons a nalfeshnee who summons 3 vrocks: (16,000 + 10,000 + 8,900) X 2 = 69800. With 4 vrocks it's 74,400.

What you have here is a tunable encounter basis. Rather than roll for a summons, I'd recommend that you tune the encounter with additional summoned demons to fit your party's experience level as players. You don't serve the rules, you are The Master of Rules (DMG p. 5). The rules serve you and your table in pursuit of fun.

Note: The variant Demon Summoning feature states that a summoned demon can not summon more demons.


Given that it's a variant rule to start with, and its purpose seems to be to avoid a never ending stream of summoned demons showing up if the dice get hot, we are still back to the DM using this feature to tune the encounter. Letting the dice drive the encounter from a hard-into-a-beyond-deadly encounter with a couple of hot rolls is letting the rules drive the DM, which is not the point of this edition of the game. If you want to only let the dice rolls drive the arrival of other demons, the difficulty of the encounter can go out of your hands. You have to decide, as a DM, if you are good with that or not.

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The Volo's Guide NPC Archdruid plus some allies; re-skin for elementals

The Archdruid (Volo's, p. 210) has conjure animals as a 3d level spell, and can cast up to 9th level spells. If you want to have him focus on conjurations, you can at your discretion keep on upcasting that spell until the Archdruid is out of spell slots1, or you can mix and match summoning spells and other spells to suit. Turning it into a "multipart encounter" can up the difficulty as discussed in DMG p. 83. (See below for details).

Archdruid spell slots for summoning:

  • 3 @ 3rd level (Standard summons)

  • 3 @ 5th level (Twice as many)

  • 1 @ 7th level (Three times as many)

  • 1 @ 9th level (four times as many)

    You can also change the spells2, to increase summoning options -- for example to insert conjure woodland beings into the 4th-level slot, and/or conjure fey into one a sixth-level spell slots -- or to reflect the elemental theme replace one of the 5th-level slots with conjure elemental:

    You call forth an elemental ... of Challenge rating 5 or lower appropriate to the area you chose appears in an unoccupied space within 10 feet of it ... At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the Challenge rating increases by 1 for each slot level above 5th. (Caveat: broken concentration turns the elemental on the caster ....) (PHB, p. 225)

    Some elemental choices include: Air elemental CR 5; Earth elemental CR 5; Fire elemental CR 5; Galeb duhr CR 6; Gargoyle CR 2; Invisible stalker CR 6; CR 5 Salamander; Xorn CR 5

Consider re-skinning Beasts to Elementals

Re-skinning beasts to elementals to get hordes of small creatures is another approach: sub in "elementals" for "beasts" and use the same CR guidance for small medium, large, and hordes. The Monster by CR type makes for a handy reference in a case like this. For example, sub in a CR 2 Gargoyle or Azer for a CR 2 beast in this re-skinning approach.

Conjure animals {elementals}
You summon fey spirits that take the form of beasts {elementals} Choose one of the following options for what appears:

One beast {elementals} of challenge rating 2 or lower
Two Beasts {elementals} of challenge rating 1 or lower
Four Beasts {elementals} of challenge rating 1/2 or lower
Eight Beasts {elementals} of challenge rating 1/4 or lower


This elemental archdruid will be very much a custom tailored boss, but will fit thematically with your idea. Hordes of Dust Mephits to strike fear into the hearts of adventurers! Example monsters: Azer CR 2; Dust mephit CR 1/2; Fire snake CR 1; Gargoyle CR 2; Ice mephit CR 1/2; Magma mephit CR 1/2; Magmin CR 1/2; Mud mephit CR 1/4; Smoke mephit CR 1/4; Steam mephit CR 1/4; Water weird CR 3

Let's build the encounter

Since the CR is 12, you'll want to boost the encounter CR by adding in a few allies, or humanoid allies like the CR 3 Archer until you get the CR for the encounter up to hard range that you are looking for to challenge your level 15 party.

Encounter budget hard ~ 4 x 15th level ~ 4,300 x 4 = 17,200 XP worth of monster/NPC. (DMG p. 82)

ArchDruid = 8,400. If you have two of them (husband and wife team?) that's 16,800, very close to your encounter budget and you get summons on top of summons.

  • But wait: this leans toward deadly. The budget guidance for two monsters is to adjust that by a 1.5 multiple, yielding over 23,000 on the budget. (DMG p. 82). For 4 15th level PCs that's (4 x 6400 = 25,600 XP for deadly) which is more deadly than hard.

    Alternatively: add a stone giant ally to fight alongside the Archdruid to boost the challenge, and to be thematically consistent.

    Archdruid = 8,400 XP and a Stone Giant @2,900 XP = 11,300 XP. Multiply by 1.5 for 16,9500 XP, not quite hard.

    Another way to peel the onion: Archdruid and 3 Archers (CR 3) 8,400 XP plus 2,100 (3x 700) = 10,500 XP). You'd multiply by 1.5 to get 15,750, but the DMG says x2 for 3-6 creatures so that's 21,000 (3-6 total monsters). Split the difference since you are on the lower end of that grouping and you get about 18,375.

    That's in the ballpark.

    Drop an archer if you think that's too much, but at this point I have to add the caveat: CR encounter math is inexact. With a very well optimized party and experienced players, what is listed as hard is often not as hard, while with an inexperienced group of players it might be harder. Tweak your archer/giant ally count according to your party's level of player expertise.

Final Caveat: The Archdruid has to concentrate on the summons, so they can't be spammed, but instead have to be summoned serially. This will likely make for a long combat encounter. This means that adding allies is probably what you want to do, since each break in concentration when the party focus fires on the archdruid means that the elemental minions may disappear. The added allies keep the party busy so that the Archdruid can keep those minions coming. This vulnerability in elemental control argues for additional giants or archers (as examples) to keep the party busy so that they archdruid doesn't have to make multiple concentration checks to keep concentration up each round.

Set it up as a serial encounter

Page 83 of the DMG has a section on "Multipart Encounters" that addresses a way to send in waves of minions / foes at the party; this is the kind of encounter design that would fit the summoning Druid, re-skinned for elementals, to fit your problem pretty well.

1 Upcasting

A monster can cast a spell from its list at a higher level if it has the spell slot to do so. (MM, p. 10)

2 Changing Spells

You can change the spells that a monster knows of has prepared, replacing any spell on a monster's spell list with a different spell of the same level and from the same class list. If you do so, you might cause the monster to be a greater or lesser threat than suggested by its challenge rating. (MM, p. 10)

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  • \$\begingroup\$ @nitsua60 I also needed to address the elemental theme, which is why I began with archdruid .... and look at what that ended up with. \$\endgroup\$ – KorvinStarmast Jul 7 '18 at 20:01
  • \$\begingroup\$ @V2Blast Thanks for adding those links. :) \$\endgroup\$ – KorvinStarmast Jul 7 '18 at 20:45
  • \$\begingroup\$ @KorvinStarmast: No problem! I considered marking the non-SRD ones and finding the MM page numbers for them... But I was too lazy for that :P \$\endgroup\$ – V2Blast Jul 7 '18 at 20:50

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