It’s important to know everyone’s goal in a conflict before you start. People fight for a reason, and if they’re willing to do harm, it’s usually an urgent reason.
The normal assumption is that the player characters are on one side, fighting against NPCs who are in opposition. It doesn’t always have to be that way, however—PCs can fight each other and be allied with NPCs against each other.
Make sure everyone agrees on the general goals of each side, who’s on which side, and where everyone is situated in the scene (like who’s occupying which zone) when the conflict begins.
It might also help, GMs, to decide how those groups are going to “divvy up” to face one another—is one character going to get mobbed by the bad guy’s henchmen, or is the opposition going to spread itself around equally among the PCs? You might change your mind once the action starts, but if you have a basic idea, it gives you a good starting point to work from.
In our continuing warehouse fight example, the sides are obvious—Og and his buddies want to do in the PCs, and the PCs want to keep that from happening.
Ryan asks Amanda about finding the smuggled goods, and Amanda replies, “If you think you can sneak in a moment during the fight to look for them, go for it. We’ll see what happens.”
The conflict starts with everyone on the main warehouse floor. Amanda decides that Og and one of his friends are going to go after Landon, two of the other thugs are going after Cynere, and the final one is going to chase after Zird.