Is a Sprite the only Pact of the Chain familiar that loses their invisibility when used to deliver a touch spell?

Question

So the Warlock Pact of the Chain says

When you cast the spell, you can choose one of the normal forms for your familiar or one of the following special forms: imp, pseudodragon, quasit, or sprite. (PHB 107)

And the Find Familiar spell states

Finally, when you cast a spell with a range of touch, your familiar can deliver the spell as if it had cast the spell. Your familiar must be within 100 feet of you, and it must use its reaction to deliver the spell when you cast it. If the spell requires an attack roll, you use your attack modifier for the roll. (PHB 240)

Now, the sprite entry says

Invisibility, The sprite turns invisible until it attacks or casts a spell, or until its concentration ends. Anything the invisible sprite is carrying or wearing is invisible as long as it remains in contact with the sprite. (PHB 310 & MM 283)

I added the Monster Manual and Player's Handbook both as references because the stat entries are identical, and neither of them ever state that a Sprite has spells it can cast.

Combining the "familiar can deliver the spell as if it had cast the spell" with the Sprite's invisibility saying "invisible until it... casts a spell", I'm sure a DM could easily rule that it then turns visible.

However, the Imp and Quasit also turn invisible but their entries are

Invisibility. the imp turns invisible until it attacks or until its concentration ends. Anything the invisible imp is carrying or wearing is invisible as long as it remains in contact with the imp. (PHB 306)

Invisibility, the quasit turns invisible until it attacks or uses Scare, or until its concentration ends. Anything the invisible quasit is carrying or wearing is invisible as long as it remains in contact with the quasit. (PHB 309)

(Their Monster Manual entries only differ by saying "concentration ends (as if concentrating on a spell)."

Going off of these, it would appear that being used as a touch spell conduit "as if it had cast the spell" doesn't make the Imp or Quasit lose their invisibility. Is this the case?

Also, if a specific spell requires an attack roll, does using them for it count as them making an attack for the purpose of losing the invisibility?

Answer 1

Channeling a spell through a familiar ends their invisibility

As you've already determined, the line about "...delivering the spell as if it had cast it" is enough to trigger invisibility ending on a spell cast.

Any of them would lose their invisibility after delivering a spell

Quasits and Imps can't normally cast spells so their invisibility actions don't list "or casts a spell" as an end condition. Since the invisibility actions in these stat blocks do list all of the offensive actions the monsters are normally capable of as ending invisibility, it's pretty easy to figure out what should happen here. So all of these monsters will end their invisibility if you channel a spell through them.

A strict RAW ruling would disagree, but 5e just isn't written tightly enough to support that kind of ruling.

Answer 2

Unless it constitutes an attack, none of these three familiars lose invisibility when delivering a spell because neither "deliver the spell" nor "as if it had cast the spell" are "casts a spell". You cast they spell: they didn't.

So, delivering a Cure Wounds would not end invisibility because there is no attack, delivering Shocking Grasp would as this is an attack.

Answer 3

All of the Pact of the Chain familiars lose invisibility when they attack. Imps and Quasits do not lose it for casting non-attack spells (which do not require concentration). Sprites lose it for casting any spell.

There is not a general rule about losing invisibility when you attack. PCs and creatures need to adhere to the restrictions on their invisibility imposed by the ability that grants it. All 3 familiars that you mention lose their invisibility when they attack as per their ability. Casting/channeling a damaging/harmful spell counts as an attack (spells with attacks, spells with saves, and spells with neither such as Magic Missile are all considered attacking the target if they do damage or cause harm). Spells which are not attacks and do not require concentration, such as healing, should not disrupt their invisibility (except Sprites which lose it when casting any spells).

Note that there are rules for a creature to maintain invisibility when attacking: Cloak of Invisibility, Greater Invisibility, Mordenkainen’s Faithful Hound, and Invisible Stalker. (There may be a few more as well.)

Items

• Cloak of Invisibility (DMG p158, legendary) - "You become visible when you cease wearing the hood."
• Dust of Disappearance (DMG, p166, uncommon) - "If a creature affected by the dust attacks or casts a spell, the invisibility ends for that creature."
• Potion of Invisibility (DMG p188, very rare) - "The effect ends early if you attack or cast a spell."
• Ring of Invisibility (DMG p191, legendary) - "You remain invisible until the ring is removed, until you attack or cast a spell, or until you use a bonus action to become visible again."

Monsters

• Quasit (MM p63, PHB p309) - "The quasit magically turns invisible until it attacks or uses Scare, or until its concentration ends (as if concentrating on a spell)."

• Imp (MM p76, PHB p307) - "The imp magically turns invisible until it attacks or until its concentration ends (as if concentrating on a spell)."

• Duergar (MM p122) - "The duergar magically turns invisible until it attacks, casts a spell, or uses its Enlarge, or until its concentration is broken, up to 1 hour (as if concentrating on a spell)."

• Sprite (MM p283, PHB p 310) - "The sprite magically turns invisible until it attacks or casts a spell, or until its concentration ends (as if concentrating on a spell)."

• Invisible Stalker (MM p192) - "The stalker is invisible."

Spells and Abilities

• Wild Surge - Sorcerer (PHB p104) - "The invisibility ends on a creature when it attacks or casts a spell."
• One With Shadows - Warlock Invocation (PHB p111) - "When you are in an area of dim light or darkness, you can use your action to become invisible until you move or take an action or a reaction."
• Invisibility (PHB p254) - "The spell ends for a target that attacks or casts a spell."
• Greater Invisibility (PHB p246) - "You or a creature you touch becomes invisible until the spell ends."
• Mordenkainen’s Faithful Hound (PHB p261) - "The hound is invisible to all creatures...."

This is my RAW interpretation. Neither the PHB nor its errata specify extra limitations to the familiars' invisibility features either under the Warlock Pact or in the monster statblocks. This is not covered in the MM statblocks or its errata either. And with no general rule about invisiblity to refer to in the core books, inserting additional rules for these familiars is not RAW. House rules covering this might be justified, but are simply not RAW.

Answer 4

Rules as Written: Yes.

Rules as Written. Unless there is an errata, which there isn't, racial abilities of monsters do what they say. That means casting through that Quasits and Imps allow them to keep their invisibility.

Rules as Written: What is an Attack?

The PHB is clear that anything that makes an attack roll is an attack, so if a spell has an attack roll, it will say "roll a ranged spell attack...", "roll a melee spell attac...k" or "roll a spell attack..."

Moreover, Jeremy Crawford tweeted this in regards to what counts as an attack for purposes of losing invisibility:

An attack involves an attack roll or doing something that the rules call an attack, like grappling or shoving. #DnD

Designer Intent: Unclear

We can only guess what the intent was in regards to the quasit and imp because I don't see the designers discussing the clauses of invisibility on the three creatures mentioned.

A number of other indivisibilities end on casting or attacking, including the spell invisibility. So it could be an oversight or mistake that the entries for imp and quasit don't contain the language "or cast a spell" because they don't have spells. Or it was intended to work the rules as written currently state. We have no information otherwise.

It's Your Game

That said, a DM could rule either way on imps and quasits. Note, that a DM could just as easily even the playing field and ignore the line for Sprite as well.

Answer 5

It can only deliver a touch spell as its reaction, on your turn, when you cast the spell, after it managed to move into position prior to your casting.

"... deliver the spell as if it had cast the spell ..."

"Invisibility. The sprite turns invisible until it attacks or casts a spell ..."

You've already answered your question. If it is treated as it has casted it, and casting causes invisibility to break, then casting the spell with touch range while the Sprite is invisible, then it breaks the invisibility.

Addendum

But one could also argue, that if it counts the spell as "... deliver the spell as if it had cast the spell ..." then any concentration spell casted this way could break invisibility due to it still is concentration. As well as anything with a with a die roll to hit, is considered an (spell) attack which breaks invisibility as well.