D&D 5E Conversation with NPCs turns into combat

[Nailen]

I'm envisioning a situation in my PotA campaign session tonight where the PCs are talking to Shoalar Quanderil in the Womford Rats encounter. I've kind of decided that Shoalar will probably get bored of the conversation quite quickly and will cast Tidal Wave at the PCs standing on the dockside.

I'm just wondering how to handle it - I know there's no 'surprise' because they all know each other are there, but I don't really want to open the conversation by saying we roll for initiative, because that hints that combat is imminent.

Should I say something like, "He starts to mutter an incantation", and give the PCs a chance to have a reaction? Perhaps the save that they get against Tidal Wave is their chance to react. And from that point, we roll for initiative.

I want to be fair.. I'm not one of those DMs who seeks to kill the party in every battle.

 

[delphonso]

I've done this a few times, and just called on people as the situation deemed natural. Then we just followed whatever initiative order that ended up being. In that case, it was only 3 players and an NPC - initiative order was:
NPC,
Player who spoke last,
Other player in conversation,
Last player to enter the room.

It'd be a bit different if the group is bigger and in this situation with a spell being used right away.
I like the save against the tidal wave being the cue to combat starting. You could also roll initiative for everyone secretly and just reveal the initiative to them.

I think the biggest thing it comes down to is how long of a fight do you think it will be. I don't own PotA - but if your players are ready to knock this dude down in two initiative passes, you might be worrying a bit too much.

 

[transtemporal]

Isn't it just initiative? If you like you could give the NPC advantage on it but he can't catch the PCs unawares. He's a hostile NPC casting a spell right in front of them. The only way he could get away with it is if he was using sleight of hand to conceal the spellcasting and even then I would give the PCs advantage on the perception check.

 

[Nailen]

Well, yes it is initiative. But would you start a conversation with NPCs by asking the party to roll for initiative?
It quite clearly signals that I'm expecting it to turn into combat.
I don't get them to roll initiative when they pop into the tavern to gather rumours...

if I did say that he starts to mutter an incantation and then we roll for initiative, what do I do for all the PCs who come before the NPC? They shouldn't react to the spellcasting, because it hasn't happened yet...
Maybe I am overthinking it.

 

[Horwath]

I would first roll Deception vs party Insight(rolled or passive, doesn't matter) if he is trying to be subtle and catch them by surprise.

If not, just roll initiative and nobody is surprised.

 

[Cap'n Kobold]

As Horwath suggested, I would have the PCs roll Insight against Shoalar's Deception when he decides to attack. Any who fail are surprised (and thus don't get to act in the first round when Shoalar casts the spell even if they rolled higher initiative than him.)

The PCs who aren't surprised and beat Shoalar on initiative are reacting to him starting the incantation to cast the spell, not to the spell going off.
Remember that a lot of actions aren't actually instantaneous. We just resolve them at a single point in time for convenience.

 

[akr71]

I would set a DC vs their Passive Perception - nothing too difficult maybe somewhere in the 10 to 15 range. Assuming someone passes this check tell the party what he is doing. The spell has verbal, somatic and material components (either a drop of water or a spell focus). Something like:

"It appears like he has stopped listening to you. Shoalar places his hand on his chest, gripping a strange amulet around his neck while the other hand begins to move back and forth in a wave like pattern. He is muttering strange words under his breath."

If they are oblivious and do nothing the spell goes off, unaffected. If the party starts shouting their intentions at you, call for an initiative roll and the spell goes off on Shoalar's turn. If they really do nothing it might even be interesting to have everyone roll a Dex saving throw and use that as initiative - they are both Dex checks, but some would have their proficiency bonus added into it. Everyone who saves acts before the spell goes off, those that do not are knocked prone and take full damage.

Full disclosure: I have never initiated combat in this manner. I only thought of it while I was writing this response and thought it would be an interesting way to jump into combat in these types of situations. They happen somewhat frequently in my games...

 

[robus]

This is why it's a great idea to pre-roll initiative at the start of a session and at the *end* of each combat. Then when combat breaks out you can smoothly insert your monsters/NPCs into the initiative order without breaking the flow at the table.

I've recently switched to doing it this way at my table and it's completely eliminated this kind of issue (and the players like it too!)

 

[Nailen]

This is why it's a great idea to pre-roll initiative at the start of a session and at the *end* of each combat. Then when combat breaks out you can smoothly insert your monsters/NPCs into the initiative order without breaking the flow at the table.

I've recently switched to doing it this way at my table and it's completely eliminated this kind of issue (and the players like it too!)

Ooooh, that's a good idea!

 

[Nailen]

As Horwath suggested, I would have the PCs roll Insight against Shoalar's Deception when he decides to attack. Any who fail are surprised (and thus don't get to act in the first round when Shoalar casts the spell even if they rolled higher initiative than him.)

The PCs who aren't surprised and beat Shoalar on initiative are reacting to him starting the incantation to cast the spell, not to the spell going off.
Remember that a lot of actions aren't actually instantaneous. We just resolve them at a single point in time for convenience.

I think I will go with this.
But I can also imagine there will be a friendly discussion at the table.