D&D 5E Swarm of Books

[koga305]

About to run a "lost library" adventure for my group of level 5 PCs, so I whipped up this monster (they will be fighting two of them for a "Hard" encounter XP total).

Swarm of Books
Large swarm of Tiny constructs, unaligned
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Armor Class 14
Hit Points 90 (12d10+12)
Speed 0 ft., fly 60 ft. (hover)
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Str 14 (+2) Dex 18 (+4) Con 15 (+2) Int 1 (-5) Wis 3 (-4) Cha 1 (-5)
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Damage Resistances bludgeoning, piercing, slashing
Damage Vulnerabilities fire
Damage Immunities poison, psychic
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, paralyzed, petrified, poisoned
Senses blindsight 60 ft., passive Perception 6
Languages ----
Challenge 4 (1,100 XP)
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Swarm. The swarm can occupy another creature's space and vice versa, and the swarm can move through any opening large enough for a Tiny construct. The swarm can't regain hit points or gain temporary hit points.
Actions
Flurry of Pages. +7 to hit, reach 0 ft., one target in the swarm's space. Hit: 26 (4d12) slashing damage, or 13 (2d12) slashing damage if the swarm has half of its hit points or fewer.

Thoughts? I tried to match traits, HP, damage etc. with the existing creatures in the book (using SurfArcher's excellent series of blogposts for guidance), although I'm worried resistance to weapon damage could be too strong. Also thinking of adding a "Weak Point" trait but not sure how to word it (a "called shot" with disadvantage allows for an automatic crit - too strong?).

 

[jadrax]

I would definitely add:

Senses blindsight 60 ft. (blind beyond this radius), passive Perception 6

False Appearance. While the swarm remains motionless, it is indistinguishable from a normal library of books.

I might also add:

Antimagic Susceptibility. The swarm is incapacitated while in the area of an antimagic field. If targeted by dispel magic, the swarm must succeed on a Constitution saving throw against the caster’s spell save DC or fall unconscious for 1 minute.

 

[Cleon]

Thoughts? I tried to match traits, HP, damage etc. with the existing creatures in the book (using SurfArcher's excellent series of blogposts for guidance), although I'm worried resistance to weapon damage could be too strong. Also thinking of adding a "Weak Point" trait but not sure how to word it (a "called shot" with disadvantage allows for an automatic crit - too strong?).

If you're worried about weapon damage resistance, why not take some or all of them out? They're only books, after all, so it might not be that difficult to slash their pages or break their spines. I could see they might be resistant to piercing damage - shooting an arrow into a book wouldn't do it that much structural harm, after all.

Giving them a Weak Point/Called Shot trait is problematic for several reasons.

Firstly, construct are usually pretty homogeneous so unless their construction specifies they're particularly prone to breakdown (e.g. some kind of clockwork creations) or have a specific point of failure (the word on the forehead of the classic Golem of Prague, an "animating gem" in its heart, or whatever) they are unlikely to be particularly vulnerable to criticals.

Secondly, they're a swarm - even if you hit a weak spot on one of them, there's still a mob of others flapping about.

I guess a weak point would make sense if there was one book that animated/controlled/guided all the other books in the swarm - a "master index" or something, so targeting it specifically would reduce the combat effectiveness of the entire swarm.

 

[koga305]

I would definitely add:

Senses blindsight 60 ft. (blind beyond this radius), passive Perception 6

False Appearance. While the swarm remains motionless, it is indistinguishable from a normal library of books.

I might also add:

Antimagic Susceptibility. The swarm is incapacitated while in the area of an antimagic field. If targeted by dispel magic, the swarm must succeed on a Constitution saving throw against the caster’s spell save DC or fall unconscious for 1 minute.

Tehehe. I love the "False Appearence" ability. Also, all of that makes perfect sense; thanks!

If you're worried about weapon damage resistance, why not take some or all of them out? They're only books, after all, so it might not be that difficult to slash their pages or break their spines. I could see they might be resistant to piercing damage - shooting an arrow into a book wouldn't do it that much structural harm, after all.

Giving them a Weak Point/Called Shot trait is problematic for several reasons.

Firstly, construct are usually pretty homogeneous so unless their construction specifies they're particularly prone to breakdown (e.g. some kind of clockwork creations) or have a specific point of failure (the word on the forehead of the classic Golem of Prague, an "animating gem" in its heart, or whatever) they are unlikely to be particularly vulnerable to criticals.

Secondly, they're a swarm - even if you hit a weak spot on one of them, there's still a mob of others flapping about.

I guess a weak point would make sense if there was one book that animated/controlled/guided all the other books in the swarm - a "master index" or something, so targeting it specifically would reduce the combat effectiveness of the entire swarm.

I suppose it's reasonable to allow slashing weapons to deal normal damage, and perhaps even bludgeoning ones.

I was thinking of that "master index" you described - if the PCs can figure out which book is in the center of the swarm, they can knock it out with a well-placed attack and take out the whole swarm. Gives an alternative for the melee characters to blindly swinging at the thing while it swirls around you. Perhaps I should just run that on the fly - if one of the PCs thinks to ask, they can make Arcana/Perception checks to figure it out.

 

[Grazzt]

I guess a weak point would make sense if there was one book that animated/controlled/guided all the other books in the swarm - a "master index" or something, so targeting it specifically would reduce the combat effectiveness of the entire swarm.

And thus was born the "Card Catalog Golem"

 

[Cleon]

And thus was born the "Card Catalog Golem"

That's the Book Swarm's Diminutive or Tiny sized relative - it depends on the size of the index cards.