Is a Pact of the Chain Warlock's quasit familiar really this effective as a spy?

Question

One of my players has a Warlock with the Pact of the Chain. This PC has a quasit familiar. If we are applying the rules correctly…

Pact of the Chain

You learn the find familiar spell and can cast it as a ritual. The spell doesn’t count against your number of spells known. 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. […]

Find Familiar

[...] While your familiar is within 100 feet of you, you can communicate with it telepathically. Additionally, as an action, you can see through your familiar’s eyes and hear what it hears until the start of your next turn, gaining the benefits of any special senses that the familiar has. During this time, you are deaf and blind with regard to your own senses. As an action, you can temporarily dismiss your familiar. [...]

VARIANT: QUASIT FAMILIAR [...] Familiar. The quasit can serve another creature as a familiar, forming a telepathic bond with its willing master. While the two are bonded, the master can sense what the quasit senses as long as they are within 1 mile of each other. While the quasit is within 10 feet of its master, the master shares the quasit's Magic Resistance trait. At any time and for any reason, the quasit can end its service as a familiar, ending the telepathic bond.

… then he can communicate with it within 1 mile and see what it is seeing.

For example, in a mission where PCs have to peek at the enemy camp, he could just stay hidden and send the quasit exploring the camp. The quasit can turn invisible and polymorph into a centipede, so it can go anywhere (even inside a building), and the Warlock can see everything.

Now, is this correct? It would seem really overpowered to me.

If it's correct, how can I limit this power in an acceptable way?

Answer 1

It's almost correct, but not quite.

There are two separate, unrelated ways to get a familiar in D&D 5e, and you're trying to combine them.

The first method is by use of the Find Familiar spell, which allows you to summon a celestial, fey, or fiendish spirit that takes the form of any of a list of creatures. This list is expanded by the warlock pact of the chain. This familiar is perfectly obedient, can be resummoned when it dies, can be hid in a pocket dimension, deliver touch spells that you cast, and everything else specified in the spell description. This method gives you a familiar with the basic stats of the chosen creature, not the "variant: familiar" traits of the chosen creature (unless your DM chooses to have that creature type appear).

The second method is by finding a quasit, imp, or pseudodragon that has the "variant: familiar" trait (which is 100% up to the DM), and enlisting it as a familiar by interacting with it. This familiar has only the traits listed in the stat block for that creature, including the variant traits, but none of the traits of familiars given by the Find Familiar spell. No pocket dimension, no touch spells, no limitations on what actions it can perform, and if it dies, it's just dead. This type of familiar is an NPC controlled by the DM (much like a hireling or other follower), and is only as obedient to the PC as the DM says it is, using the MM entry as a guide.

Now that we've established how things actually work, we can address your real concern. Your warlock can't yet communicate at a great distance, but he can soon. There is a warlock invocation available to him called Voice of the Chain Master that does the same thing, but with unlimited range on the same plane. As you've realized, this ability has some incredible potential, especially for scouting.

It's not any more powerful than other options and should not be limited.

Let's compare it to some other invocations. There's one that lets a warlock cast Disguise Self as at will. This would let him see a guard, and appear exactly like that guard and just walk around the enemy camp unimpeded. Or maybe impersonate the leader of the camp and just take it over without even a struggle. There's another invocation that lets the warlock cast arcane eye at will, which gives you a way better scout than an easily killed creature. A familiar, even an invisible one, still has to succeed on a Dexterity (stealth) check to avoid being heard and then easily killed. An arcane eye does not.

So, in order to fully utilize this scouting ability, your warlock has to pick the chain pact and spend one of his few, precious invocations, both of which are huge opportunity costs. He deserves something in return. This something is you not limiting it. It already has a flaw in still being able to be killed by anything that hears it, or smells it. That's right, just about any pet wolf is going to be enough to catch this familiar. It doesn't need any more limitations.

Answer 2

No, it's not overpowered.

Yes, a Familiar is very useful, particular in the scouting and spying role.

The Warlock and his party still have to defeat whomever is there to be found or spied upon, if defeat achieves the story objectives. There is ample opportunity for difficulty to be adjusted without trying to nerf a class capability.

How can I limit this power in an acceptable way?

You don't need to, since you are dealing with two different ways to get a Familiar.

1. If you feel that the Variant Quasit gives too much benefit, then use the plain Familiar. The Warlock risks being detected when using the Quasit as a scout (invisible or not) as he's got to be within a hundred feet of it. In some scenarios, particularly outdoors, that's not very far. (From home plate to first base is 90 feet). If you are treating the Variant Familiar Quasit like the summoned Familiar, then you are homebrewing something that makes the Familiar more powerful than intended.

2. If, per your example, the Warlock Quasit turns into a centipede, the centipede sees things -- but can it hear them? How do centipedes hear? While this gets down into granular / simulationist detail, the vibration sensing that centipedes have may not include understanding speech. Its sight may be different from your Warlock's senses. A giant centipede has this sensory package (Basic, DM, p 23):

   Senses blindsight 30 ft., passive Perception 8

   So maybe it cannot hear but rather senses vibrations. Maybe its blindsight isn't as clear as human or elven vision. With that in mind, you could modify what a Quasit's senses pass to the Warlock based on the form it takes.

3. If using the variant rule Quasit Familiar, the DM role plays the Quasit. This will add depth to the Warlock-Quasit interactions. The Monster Manual variant isn't the same as the summoned Familiar from the spell.

   The Quasit can serve another creature as a familiar ... at any time and for any reason, the Quasit can end its service as a familiar, ending the telepathic bond.

   You role play a Quasit. If you feel that it is being abused or that the Warlock is no longer worth serving, the Quasit can cop an attitude and leave. This variant requires the Warlock establish a relationship with the Quasit, not just use it as a disposable asset. This opens up role playing opportunities for you both.

   Example: Warlock says "I want you to scout over there, and tell me what you see." Quasit's feeling grumpy that morning and responds "You can want in one hand and defecate in the other -- see which one fills up first, mortal!"

(Credit to @J.A.Streich). Pact of Chain gets you the Quasit under the normal terms of the Find Familiar spell, rather than the Familiar Variant rules in the Monster Manual. If a Warlock took a different pact, like Pact of Tome, the Warlock could if the DM allows it use the variant rule to gain a Familiar as described in the Monster Manual. The variant rule doesn't use the Find Familiar spell, so the Quasit can't be re-summoned when it is killed, unlike a Familiar summoned via the spell.

Answer 3

Polymorphing wouldn't be that effective RAW. In the Quasit's Shapechanger description, it says that it transforms into a beast form that resembles a bat, a centipede, or a toad. It isn't actually turning into a centipede, it's just turning into something that's close to a centipede. Additionally, it says that the statistics are the same in each form, meaning its centipede form is the same size as its regular form (about 1-2 feet). So its centipede form is less an unnoticeable insect and more of a disgusting abomination of a giant bug-looking monster.

Answer 4

If you read the descriptions again, you would realize that you can only communicate with the quasit within 100ft, you can sense what it hears and sees within a mile. You could not command it while it's outside the 100ft perimeter. The quasit is essentially on its own outside the 100ft perimeter.

Answer 5

First it says quasit serves master, not that PC control it. Second, seeing within 1 mile doesn't mean they can communicate normally.

This is not OP in my opinion, there are far more dangerous tools than this. For example I have an owl familiar, that thanks to its dark vision and high perception makes it really hard for DM to surprise us at all! And it can fly around enemy camp as well (not inside buildings in some cases).

And don't forget that if something is invisible it doesn't mean it's undetectable. Well trained hound will smell such demonic presence (sulfur!), and a centipede can be easy prey for stray cat or even common rat.

Familiar is a tool that has its limits. You could say then that low level hafling thief is OP because of it's gigantic stealth compared to enemies.

Answer 6

Quasits are not going to be as helpful as your warlock thinks they are

Reading from the SRD, here this is the first sentence about Quasits:

Although quasits thirst for victory and power as other demons do, they are cowards at heart.

When you combine this with the description that you posted above:

At any time and for any reason, the quasit can end its service as a familiar, ending the telepathic bond.

And finally look at their alignment:

Alignment: Always chaotic evil

You get the full picture.

Yes, if your Warlock has somehow managed to get an always chaotic-evil cowardly demon to serve him to the death, then sure, it's pretty overpowered for the reasons you mentioned. However, as a DM you should probably not allow those circumstances to ever occur. A quasit will work with your warlock as long as it suits the quasit, but the minute the warlock asks them to go into danger, or asks them to do something even slightly selfless, or even as soon as the quasit gets bored, the quasit will just leave. Or say he'll do whatever he was asked to do and then leave. Or say he'll do it and immediately switch over to the enemy's side and give away the warlock's plans. Or do what was asked, wait until the party is asleep, use their invisibility to steal all of the party's magical items and then leave. Or wait until the party gets some loot, polymorph into a giant ape, punch the warlock in the face, steal the loot, and then leave.

In reality, the quasit will probably be more of a hinderance than a benefit to the party. At a minimum, your warlock certainly shouldn't be able to command the quasit to do anything other than what the quasit wants to do naturally (and being chaotic evil, it's probably not what the warlock wants). More likely, the quasit will scheme with and against the warlock at all times, and will probably immediately recognize its potential power (being the eyes and ears of the party on scouting missions). As a DM, you now get to RP an NPC who can be used to bring down the party, or at the very least be a thorn in your warlock's side until they change their familiar back to something more normal.