dnd 5e – 5e creatures that ignore armor?

I’m trying to homebrew a nasty hornet swarm with some added attacks to make it more dangerous. One of the ideas that I had was to make the hornets crawl under the armor/clothes when attacking, thus ignoring the armor/shield bonus. I was wondering if there are already mechanics for something like this in the game or monsters that do something similar. I could not find anything during my search, but my book access/knowledge is not absolute unfortunately.

If there are no rules for it, I would probably give them an ability like:

Attack from within By spending 5 feet of its movement, the swarm can crawl in between the armor of the target, attacking them directly. Use a target AC of 10 + Dexterity modifier for any attacks made in this state unless the target is wearing protective clothing, has unarmored defense or similar. This effect ends by the end of the swarm’s turn when it crawls back out.

dnd 5e – Iron Flask and spell-summoned creatures

If I’m a wizard on the material plane and I cast Summon Lesser Demons, then capture one of the demons with an Iron Flask, what happens to the captured demon when the spell ends one hour later? Does it disappear and return to its home plane, leaving the Flask empty, or is it bound by the Flask now?

dnd 5e – Are tiny creatures carried in a backpack protected from AOEs?

It might vary a bit depending on the spell, and there may be exceptions, but as a general rule I would say “yes”, if they are entirely hidden inside it. If the backpack is open, or the tiny creature is peeking out of it, then “no” — they could be affected. But most spells are defeated by total cover.

Can a swashbuckler parry creatures he cannot see if he has blindfight and combat reflexes?

Can a swashbuckler parry an attack from an invisible creature or creature they cannot see if they can make AOOs while flatfooted via combat reflexes and have blindfight?

dnd 5e – Do features that say they let you see invisible creatures and objects actually let you see invisible creatures & objects?

If your reading of a feature called See Invisibility is that you cannot see invisibility, your reading is incorrect.

It’s quite simple, really. The intended function of these features is so abundantly clear, that any argument that concludes that they do nothing can be dismissed out of hand.

In fact, this principle applies in general. If you read a feature, and know what it is supposed to do, but you determine that the feature actually does nothing, you can know without any doubt that your conclusion is wrong.

There is just no meaningful application of reading the rules this way.

Sure, maybe you found a bug in the game. But there is no reason at all to make this ruling at the table. This ruling contributes nothing of value to the game.

Sorry wizard, after reviewing the rules, your feature called See Invisibility does absolutely nothing.

The Dungeon Master’s Guide states:

The D&D rules help you and the other players have a good time, but the rules aren’t in charge. You’re the DM, and you are in charge of the game. That said, your goal isn’t to slaughter the adventurers but to create a campaign world that revolves around their actions and decisions, and to keep your players coming back for more!

Ruling that See Invisibility does nothing is that exact opposite of this. This ruling puts the strictest possible reading of the rules in charge, to the detriment of everyone’s fun.

dnd 5e – Does a 3rd-level Wolf Totem barbarian give advantage to friendly summoned creatures and other allies that are not strictly speaking “friends”?

There’s no clear definition of “what makes something friendly?” that I could find, but I found enough pointers to answer the questions. I’d say all of the things you mention almost certainly qualify as “friendly”.

Regarding anything you summon: all the summoning spells I found explicitly include the line “the creature(s) are friendly to you”, so they are friendly.

Regarding the pet, that would basically up to the pet’s owner, but they’re a player at your table so it’s up to them (and I don’t see why they would not want the beast to be your friend; other than maybe roleplaying reasons but that’s between you and them)

Regarding other NPCs: the paragraph on “social interaction” on page 185 of the PHB states:

In general terms, an NPC’s altitude toward you is
described as friendly, indifferent, or hostile. Friendly
NPCs are predisposed to help you, and hostile ones are
inclined to get in your way. It’s easier to get what you
want from a friendly NPC, of course

So I’d say anyone you hired to protect you, would fall under the “predisposed to help you”, simply because that’s what you’re paying them to do.

Animate Dead doesn’t explicitly say it makes them friendly, but they do obey your instructions. The Cleric’s Command Undead does state explicitly that it makes the target friendly to the Cleric.

Based on the social interaction paragraph, a controlled creature is “predisposed to help you”, even though in this case it’s through coercion. I’d say any form of direct control is then enough to be considered friendly, but you might want to check this with your DM to see if they agree with the idea.

dnd 5e – Can an Echo Knight fighter’s Manifest Echo move through another creature’s space?

I would like to know if an Echo, created by the Manifest Echo ability of an Echo Knight, can move through the space of another creatures (hostile or not)?

I know characters cannot normally move through an enemy’s space, and can move through an ally’s space with some movement cost. But by the rules, an Echo itself is not considered a creature, and instead is listed as “image” and an “object” tweet by Jeremy Crawford.

dnd 5e – Do weapons looted from creatures that are larger than Medium in size retain their damage when wielded by Medium-sized PCs?

Technically speaking, yes. The looted weapon will still deal extra damage.

Big monsters typically wield oversized weapons that deal extra dice of damage on a hit.

The “that” is pretty clear – the weapons deal extra damage, not the monster.

However, you should be extremely cautious in making these rules (and weapons) accessible to players. The rules on creature size are in the PHB, but these rules are in the DMG. They’re not meant to be easily accessible to players.

A player who is making a conscious effort to gain advantage on their attacks can do so fairly easily. That makes wielding oversized weapons a pretty nice option for any player who wants to build around it. At the very least, if you’re planning to allow this, consider implementing the suggested rule that it is impossible to use a weapon two sizes too big.

How many actions does a Bida need to use to sustain its Improved Grab on multiple creatures?

A Bida has grabbed three people with its tail via its Eight Coils and Improved Grab ability. How many actions does it need to use to keep all three of those people grabbed? 1? 3? I’d guess it works like Constrict (one action for all of them), especially since it’d be impossible to grab 8 people otherwise.

dnd 5e – Does the spell Destructive Wave allow choosing hidden creatures as targets?

Many spells where you can select targets specify you must select targets that you can see, for example Seeming:

This spell allows you to change the Appearance of any number of creatures that you can see within range.

However there are some spells which don’t require seeing. I am considering the Paladin spell Destructive Wave for a character of mine (for its ability to knock targets prone), and it has this text:

You strike the ground, creating a burst of divine energy that ripples outward from you. Each creature you choose within 30 feet of you must succeed on a Constitution saving throw or take (damage and be knocked prone, save for half damage)

I would think this clearly allows using this spell even when blind, or against invisible creatures, if the target is not hidden. Also, line-of-effect rule is also in effect, because why wouldn’t it be, right? (This is not the question, just assumptions I am making, and I’m pretty sure the DM will also make.)

But is it allowed to choose creatures which are also hidden from the caster, when the spell doesn’t require caster seeing the targets?

There are at least these cases to consider:

  1. Creatures which the caster knows about, but which are hidden, so their location is uncertain to the caster. They may or may not be within range, but the caster wants them to be affected if they are.
  2. Hidden creatures, which the caster doesn’t even know about, but the caster wants to choose every creature within 30′.
  3. Creatures the caster knows, but has no reason to think they might be within the spell range.