D&D 5E Warlock in party with Quasit breaking story

[Decorayah]

Hello guys. I'm a novice DM and am running a party of 4 through a story of my own making. I'v spent quite a lot of time coming with the story and it is my focus in the campaign. I often try to create suspense, mystery, a feeling of exploration etc. All is going well except one thing: we have a warlock/sorcerer multi-class in the party with pact of the chain. He has a quasit familiar that can fly, can be used for his senses up to a mile away, is invisible and can shape change. This basically means he always knows everything in advance. Also the quasit is a slave, meaning he can't disobey. Here's an example.

1. There is a small mysterious castle in the distance. He just sends the quasit to fly over and scout everything.
2. There are guards everywhere. Quasit doesn't care: he's invisible.
3. There is a locked door. Quasit doesn't care. He transforms into a small centipede and enters through the lock.
4. Oh no it's been detected. Warlock can just instantly recall it.
5. Oh no it's killed. Warlock can have another within an hour.

Seriously? I can't create any surprises or suspense or anything when he knows everything in advance. I have 2 questions:

1. Is everything I said here valid? Can he really do everything I described?
2. If it is then can any more experienced DMs tell me how I can counter that without just saying every creature in the world has true sight because that would make zero sense.

Any help is greatly appreciated because I am feeling quite powerless to present the story I want and don't want to just say "DM rule. You can't use a Quasit. Deal with it"

 

[CapnZapp]

Hello, Decorayah. Welcome to the forums and welcome to D&D

 

[Decorayah]

Thanks

 

[Bitbrain]

What about having certain dungeons and other locations important to your story be under the effects of hallow spells and magic circles?
In this way, the quasit cannot scout out the place first because it can't get in.

 

[akr71]

Does the familiar just do a fly over for scouting purposes? Just get the lay of the land and figure out how many guards, etc? Or does it explore every room of your castle example before hand?

I ask because if I were in that party, I would get bored waiting all the time and say to my companions (in character) that the familiar is getting all the fun exploration while we sit by the roadside and rot.

Alternatively, have a wandering monster stumble upon them while the familiar is scouting the way, or even an ambush! Just because it is invisible and can fly doesn't mean it will spot everything, or even most things. (Int 7, Wis 10, Passive Perception 10) Make the Quasit roll some Investigation and/or Perception checks before you hand over any obvious details

Stick with it, be imaginative. The warlock is using his/her head and shouldn't be penalized for it. Oh, and maybe there is no keyhole for it to crawl through.. not all doors have a lock.

 

[Fanaelialae]

Quasits can't fly, but everything you've said is true of the imp familiar, so I'm assuming that's what you meant.

For starters, familiars do make excellent scouts. That said, invisibility isn't a "No one can ever detect me" card. It simply allows you to hide without needing something to hide behind. Which means that it still requires a stealth check (unless the DM rules otherwise, of course) to go unnoticed. It's not magically silenced, after all.

If the enemy detects it, it can be resummoned with a short ritual right? Well, yes, but unless the creatures in the castle are mindless zombies or something, they might get suspicious that an invisible devil was flying around their castle. Now the guard patrols are increased and on high alert.

Time pressure can also be useful here. Perhaps an ally of the PCs' is to be executed in a few hours. Sure, they can send the imp to scout the castle, but by the time the imp is done it will be too late to mount a rescue.

As for turning into a centipede to crawl through locks, you're the DM. You're well within your rights to rule that the imp can only turn into a bigger (12 inch) centipede, which is too large to fit through most locks (but may be small enough to crawl under some doors).

Finally, and most importantly, keep in mind that this a feature that the player selected at the cost of other features. It's fine to limit it, but be careful not to limit it to the brink of being useless, because the player is likely to get (in my opinion, justifiably) upset. You don't have to let the imp get away with murder, but let him be useful and scout at least some of the enemy positions. It's a matter of feeling out the right balance. Don't be so concerned about your story that you forget to keep the players' fun in mind. It's okay (and generally expected) for the story to change and evolve during play.

 

[Warmaster Horus]

That's one of the things you need to deal with when you've got a PotC warlock in the party. Others have put in good ideas about how this should not be a sure-fire 'know everything' button but you need to still respect the player's capabilities. Heck, have someone in the dungeon send their own invisible familiar out to find the party and see how they like it (I've done this a couple of times).

 

[Krachek]

Assume it.

It is like special Ops with Drone, Satellite scanning, etc..
So dont put too much energy to make surprise there. Put your time elsewhere.

But you can also count that Imp and Quasit are not the only one in the world. Invisibility is an old trick in a fantasy world.
Dogs relying on smell, Sealed door, Trained giant bat, Dust sprinkling trap, you can add some challenge once in a while.

 

[Decorayah]

What about having certain dungeons and other locations important to your story be under the effects of hallow spells and magic circles?
In this way, the quasit cannot scout out the place first because it can't get in.

Yeah I do that but I can't do it at all times. Most of the time in the story the party is out exploring different islands that are unrelated. For most of the places they visit there is little reason to have magic defenses up. Basically the quasit turns a:

"Oh a mysterious castle. Wonder what's inside? Is it deserted? Is there anything creepy going on? Let's do a perilous attempt at finding out and maybe we'll find interesting treasure?

into

"Oh a mysterious castle. Give me a moment. Ok it has 12 guards. They seem to be skeletons. They aren't heavily armored so probably not that strong. There is a big chamber. Inside there is a bigger skeleton and some zombies. There is a chest behind it. I think we should be fine going in."

In my opinion the first one is more interesting.

 

[Decorayah]

Does the familiar just do a fly over for scouting purposes? Just get the lay of the land and figure out how many guards, etc? Or does it explore every room of your castle example before hand?

I ask because if I were in that party, I would get bored waiting all the time and say to my companions (in character) that the familiar is getting all the fun exploration while we sit by the roadside and rot.

Alternatively, have a wandering monster stumble upon them while the familiar is scouting the way, or even an ambush! Just because it is invisible and can fly doesn't mean it will spot everything, or even most things. (Int 7, Wis 10, Passive Perception 10) Make the Quasit roll some Investigation and/or Perception checks before you hand over any obvious details

Stick with it, be imaginative. The warlock is using his/her head and shouldn't be penalized for it. Oh, and maybe there is no keyhole for it to crawl through.. not all doors have a lock.

If it was just a fly over I would be fine. Problem is the warlock knows he can do more and starts entering every single room (locked or not) and scouting. All possible surprises, ambushes or interesting plot developments get revealed. I get your character's thinking and I think it's adequate but our party is very pragmatic and doesn't do anything like that. They just sit around and wait for as much information as possible. It honestly gets boring at a point but they go on.

I can do the wandering monster move but if it happens way too often (and they use that quasit every single time) it just starts looking unnatural and forced. Making it roll investigation/Perception is a good idea.

I don't want to penalize the warlock. On the contrary - I want to not limit his ability and find a way to keep the story going. Problem is the story gets more predictable and boring because of this ability. Basically he makes the campaign worse for both himself and everyone else in a completely legal way. That's what I want to stop.