Mordenkainen's Tome of Harnessing - A Player utility guide for the new creatures

[Renduaz]

Prelude

Tell me, when you look at a creature's entry in your book from a player's perspective, what do you see? Merely a foe to overcome, or a tool to be untapped for untold benefits? If it's the latter, or if you desire to know more about the latter, then this Tome of Harnessing is just for you. A list of new creatures in the right hands isn't just a list of challenges to overcome, it's actually a list of new spells, new abilities and new opportunities, waiting to be unlocked. This document has been compiled to include all the interesting new entries from Mordekainen's Tome of Foes.

What's Inside

The Tome of Harnessing is in fact a supplement to my longer-standing "The Adventure's Guide to Abusing Monsters" (https://docs.google.com/document/d/1yGW6B68wAsR42Eo4qbg9TK8x10RcQsH2R1lQIoCiE3Y/pub), which contains a preliminary index of the terminology and functions discussed in the Tome of Harnessing, and is therefore absolutely vital to read, followed by a much longer bestiary drawn from all of the former books.

In short, both the Adventure's Guide and the Tome of Harnessing act as a sort of reference sheet and often a more mechanical utility guide for all the myriad of ways in which a player in a campaign can use an encountered creature for various advantages upon subduing it, whether it's through Controlling ( Dominating/Charming/Similar ) it, Transforming into it ( True Polymorph/Shapechange/Similar ), Extracting certain components from it, Allying with it or Trapping it, which are the distinct categories portrayed in both documents. Some utilities might be plainly visible and ready, in which case they are mentioned as worthy references for quick inspection, others require much more complex methods to fully derive value from. All of the details surrounding the subject of exactly how one would go about doing all of this is elaborated upon within the beginning of the Adventure's Guide.

The Tome of Harnessing is neatly arranged with a Table of Contents, name of the Creatures, the categories of utilization which are most applicable or possible for them, and a section for Traits, Abilities and Commentary for anything else, although I have not used it very extensively. The Tome of Harnessing shows how you may:

* Pry an Allip's secrets to their fullest extent

* Employ a Berbalang as an essentially limitless scout and spy

* Command an indestructible Boneclaw, potentially forever

* Use a Canoloth as a mobile Teleportation ward

And other interesting tidbits that caught my attention while browsing Mordekainen's Tome of Foes.

FAQ

Please note that reading the first chapter of the Adventure's Guide is imperative to understanding the Tome of Harnessing in context.

Why isn't every creature covered here?

Both the Adventure's Guide and Tome of Harnessing, for reasons of expediency and usefulness, do not discuss any creatures which do not have some kind of uniqueness ( Whether it be in Traits, Abilities, Type or even Challenge Rating ) or unusual talent, nor creatures whose usefulness does not warrant much thought. For example, a creature with a common damaging attack or ordinary spell, no matter how much damages it does, will hardly warrant a spot since it's utility is in plain sight, and probably shared by most other creatures to some extent, strength aside. Furthermore, a creature whose unique attribute is either an equivalent or lesser variant of an attribute of another creature that has already been included will likewise not be added.

Nontheless, the Adventure's Guide provides a debriefing on how to make use of any creature you might encounter on your own right, and the Bestiaries of both documents can inspire you to accomplish similar feats with any other creatures you set your mind to.

How do you control creatures with Charm immunity?

A creature with a Charmed condition immunity that is assigned a "Control" category will almost always be of a type that can be controlled to various extents with spells and abilities that do not qualify as Charms, as discussed in the Adventure's Guide. Although there are also a few ways to bypass that universally, depending on who you ask.

Is everything always going to go perfectly?

No, and nobody could ever make any D&D guides with that criteria in mind.

Do you have to be a Spellcaster in order to make use of this?

Unfortunately, due to the nature of the tasks that we are dealing with, a vast majority of these methods are only available to heavy spellcaster classes. However, even if you can't do some of the things yourself, you could always suggest them to someone in the party who can, if ever you find a need.

Why are some Traits or Abilities empty?

They are left empty whenever there is nothing of particular merit to be said about them. Sadly Mordekainen's Bestiary is naturally much shorter than the MM and Volo's combined, so there is also significantly less content, but it still makes for a worthy addition and reference tool in my opinion.

Link (https://docs.google.com/document/d/1MVFvKpimYuMHX04UkaDIfMlGkKZghB4nJWTz-oWXiIE/edit?usp=sharing)

[Daithi]

You missed the NightWalker. It's a CR 20 undead that easily fails its save for a necromancer's Control Undead ability, and it's not smart enough to repeat save attempts, so you get permanent control.

[Renduaz]

You missed the NightWalker. It's a CR 20 undead that easily fails its save for a necromancer's Control Undead ability, and it's not smart enough to repeat save attempts, so you get permanent control.

Saw it, but thought it was too straightforward, even though it is indeed a perfect candidate for Command Undead in terms of CR and INT. But come to think of it, it's indeed pretty rare among Undead in the MM and Volo's too, so thanks for pointing that out, I'll add it for those reasons.

[Zene]

One problem with the Nightwalker is it doesn't know any languages. So best to have a Tongues spell readied to cast on it right after Command Undead is used. (Some forms of telepathy, like the GOOlock's Awakened mind, wouldn't even help because the target still needs to know a language). And then issue it standing commands--like don't harm any of your allies, always stand 35'' away from you and your allies, and protect you from harm-- so you don't always have to have Tongues up.

Anyway, Renduaz, thanks so much for doing this. I always appreciate your thoughts, and I haven't had the time yet to fully digest MToF. Reading through your guide now; I'll come back with any suggestions.

::Edited to add::
Great stuff!
A couple comments:
1) Your entry for Hellfire Engine mentions True Polymorph. The Engine has the Immutable Form trait, so my understanding is TP wouldn't work on it.
2) This might be too niche for your guide, but personally, I love the Drow Inquisitor's Discern Lie ability. No check, no save, it just knows. Seems useful.

[MaxWilson]

Prelude

Tell me, when you look at a creature's entry in your book from a player's perspective, what do you see? Merely a foe to overcome, or a tool to be untapped for untold benefits?

That's a neat article. Two comments: you list Magic Jar as applicable to All monsters, but in 5e it only works on humanoids. Also, I didn't see you mention the True Polymorphic trick for stashing monsters: depending on how your DM interprets "permanent," the spell may still be Dispelled after you make it permanent. If so, you can use it to turn monsters (e.g. Purple Worms) into objects (e.g. pebbles) for later use, instead of killing them.

How do you use a Purple Worm pebble? Toss it at another monster (using your object interaction) and cast Dispel Magic on it. It's basically a one-shot magic summoning item that takes a spell and an ability check to activate, with no real upper limit on the strength of the monster it summons. (Especially great for Abjurors, Lore Bards, and/or anyone with Bardic Inspiration currently, to make Dispel Magic more likely to succeed. Sorcerers, Warlocks, Paladins and Bards can use Glibness here for guaranteed activating, if they're planning on using a whole bunch of pebbles.)

The strength of the monsters you produce scales with the strength of the monsters you usually fight. Nonlethal damage is relatively easy to inflict in 5e (any melee attacker can inflict nonlethal damage at no penalty; rather, can declare that an enemy is knocked out instead of killed, when reducing them to 0 HP) and you can use that time window while they're unconscious to use up legendary resists, cast Bane/Bestow Curse/Feeblemind if desired to increase the chance of success, and finally cast your True Polymorph on Big Bad Legendary Monster of your choice.

Just try not to pick a monster that's going to hold a grudge against you when you dispel the Polymorph + Feeblemind.

[Tanarii]

That's a neat article. Two comments: you list Magic Jar as applicable to All monsters, but in 5e it only works on humanoids. Also, I didn't see you mention the True Polymorphic trick for stashing monsters: depending on how your DM interprets "permanent," the spell may still be Dispelled after you make it permanent. If so, you can use it to turn monsters (e.g. Purple Worms) into objects (e.g. pebbles) for later use, instead of killing them.
What happens when someone casts a Dispel Magic on you? Or your pouch full of pebbles?

[MaxWilson]

What happens when someone casts a Dispel Magic on you? Or your pouch full of pebbles?

(1) Nothing, by RAW. Dispel Magic's effect is that "Any spell of 3rd level or lower on the target ends" [and higher-level spells require a check]. But True Polymorph wasn't cast on you.

(2) Not a legal target. You get to cast Dispel Magic on one object, not a dozen objects all in a pouch.

Watch out for Antimagic Field though. :-) If you can manage to keep your pebbles in a Heward's Handy Haversack or something, that would be ideal, because then it will just shut off access instead of turning all the pebbles temporarily back into angry monsters.

[Unoriginal]

You know that learning an Allip's secret in full mean you're turned into an Allip, right?



When a mind uncovers a secret that a powerful being has protected with a mighty curse, the result is often the emergence of an allip. Secrets protected in this manner range in scope from a demon lord's true name to the hidden truths of the cosmic order. The allip acquires the secret, but the curse annihilates its body and leaves behind a spectral creature composed of fragments from the victim's psyche and overwhelming psychic agony.

Blasphemous Secrets. Every allip is wracked with a horrifying insight that torments what remains of its mind. In the presence of other creatures, an allip seeks to relieve this burden by sharing its secret. The creature can impart only a shard of the knowledge that doomed it, but that piece is enough to wrack the recipient with temporary madness. The survivors of an allip's attack are sometimes left with a compulsion to learn more about what spawned this monstrosity. Strange phrases echo through their minds, and weird visions occupy their dreams. The sense that some colossal truth sits just outside their recall plagues them for days, months, and sometimes years after their fateful encounter.

INSIDIOUS LORE An allip might attempt to share its lore to escape its curse and enter the afterlife. It can transfer knowledge from its mind by guiding another creature to write down what it knows. This process takes days or possibly weeks. An allip can accomplish this task by lurking in the study or workplace of a scholar. If the allip remains hidden, its victim is gradually overcome by manic energy. A scholar, driven by sudden insights to work night and day, produces reams of text with little memory of exactly what the documents contain. If the allip succeeds, it passes from the world-and its terrible secret hides somewhere in the scholar's text, waiting to be discovered by its next victim.



And "the result is often the emergence of an allip" doesn't mean "sometime, the creature does not turn into an allip", it's "sometime the knowledge is cursed in other ways". For example, Vecna cursed his stuff to transform people into Nothics, not Allips.

[Tanarii]

(1) Nothing, by RAW. Dispel Magic's effect is that "Any spell of 3rd level or lower on the target ends" [and higher-level spells require a check]. But True Polymorph wasn't cast on you.

(2) Not a legal target. You get to cast Dispel Magic on one object, not a dozen objects all in a pouch.
Okay, that's a reasonable interpretation.

I've also always ruled it as all spells affecting the person and objects on the person targeted, when it's a person targeted. So if you've got a bunch of goodberries on you plus a bless, they're all valid for a Dispel Magic targeting you.

Meanwhile "Objects" is for standalone objects, to me. A petrified statue, for example.

[MaxWilson]

Okay, that's a reasonable interpretation.

I've also always ruled it as all spells affecting the person and objects on the person targeted, when it's a person targeted. So if you've got a bunch of goodberries on you plus a bless, they're all valid for a Dispel Magic targeting you.

Meanwhile "Objects" is for standalone objects, to me. A petrified statue, for example.

Sure, you always have to adapt Internet advice to the rules in the game you're actually playing. I myself run Dispel Magic completely differently than RAW: Dispel Magic N requires a check to dispel spells up to level N, and cannot dispel more powerful spells at all. (This is partly because I find it unpleasant and unaesthetic that major scenario spells like Teleport Block, a.k.a. Mordenkainen's Private Sanctum when recast enough times to become permanent, can be trivially dispelled with a bog-standard Dispel Magic or three. Geas is another example of a spell that Dispel Magic renders largely useless for DM scenarios. And some creatures, like Glabrezu, get at-will Dispel Magic, and I didn't want that to be an automatic "break any enchantment just by retrying" ability.)

The point is, people should use Internet advice as a source of potential ideas, but you always have to evaluate that advice in the context of the game your DM actually runs. As I alluded to above, if your DM runs True Polymorph as truly permanent, the spell winds up playing a completely different role in your arsenal. (Instead of using it to turn real monsters temporarily into monster grenades, you use it to turn objects into real monsters for your army, or to turn monsters in your army into more useful monsters. Arguably this is the more powerful and desirable ruling from a player's perspective, although it doesn't allow the alternate usage of "turn myself into a Shadow Dragon until another PC Dispels the spell." Each ruling is exploitable in its own way.)

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And "the result is often the emergence of an allip" doesn't mean "sometime, the creature does not turn into an allip", it's "sometime the knowledge is cursed in other ways". For example, Vecna cursed his stuff to transform people into Nothics, not Allips.

That's an interesting opinion, but "result is often the emergence of an allip" could just as easily mean "sometimes the creature makes its saving throw or does not fit the qualifications, and is unaffected by the curse." Ultimately it's up to the DM.