After you’ve created the quest, click ok and re-open it so that all of the tabs are enabled. Click on Quest Alias, right click in the blank box, and select New Reference Alias (Figure 2).
Note that you will have NO aliases here at this point, we will be CREATING 1 and 2 soon.
Note: Allow Reserved doesn't NEED to be checked. It just means that if this actor is reserved by another quest, it's okay to have them in this quest too. This applies to all the aliases. It is recommended you check it though.
Note: If one of your aliases isn't filling, make sure that the actor of the alias has a reference in game, with a Persist Location set on the reference. The persist location should be set to the location that the actor is usually in. If you can't figure this out, just make the alias Specific Reference and point it directly to the reference of your NPC.
Check Allow Reuse in Quest for the Unique Actor aliases! This is because, as they fill:
Actor 1 will fill with personA or personB. This means that Actor 2 HAS to fill with the person NOT chosen by the other alias, because neither Actor alias is marked as reusable (can have more than one alias filled with the reference in the quest). However, b/c the aliases for the persons will also have the reference of something in the Actor 1/2 aliases, no matter what, those MUST be reusable, or the aliases will not fill, the quest will not start, and your scene will not play.
Right click in the large box in the middle and select new actor (Figure 8) and choose the first actor that’s going to be speaking (Figure 9). Do this for both actors.
Also be sure to tick the box Begin on quest start and Stop quest on end. This makes sure the scene quest stops when the scene stops, and begins when the quest begins. Without it your scene probably won't work. (Thanks Oscar for the reminder!)
Edit, comment from soupie:
"Under "Node Conditions" its a good idea to add a couple of conditionals, Event Data, Actor1, Actor2, IsInInterior == 0 or 1. Otherwise NPC's that are indoors will sometimes travel outdoors etc to talk to each other which can take some time. Also GetDistance <= 200 or similar so that one will then walk towards the other and will finally speak when in range (they'll talk over quite long distances otherwise)"
Note that this is NOT necessary for it to work, and vanilla quests don't do this, but it could improve how your scene looks/works.
You can create as many dialog scenes as you want, but remember that stacked nodes will play from the very first one to the very last one, while each random one has a random chance of playing.
If you have any questions or revisions, feel free to comment below or contact me.