So we had an all-out fight (conflict) with an Owl. Two of the characters were in on it, the other character was off busy somewhere else. We had just resolved his scene, so the other player said “can I get in on the conflict?” I made a quick judgement and said, “If the conflict goes into another round you can join at the beginning of that one.”
The conflict went through its first three actions as normal, and everyone was still in it. I let the third player jump in with his character, contributing +1D to his team’s disposition in the middle of the fight, as well as fully joining the conflict, taking one of the actions.
After the fact, examining the game, I feel like this is wrong. I should have just told him “You can’t full-on join the conflict after it’s started. You can just contribute helping dice to one side.”
I think Luke addressed this in another post a few months ago. From what I remember, another player can join in and act as usual, but doesn’t get to contribute disposition after the fact.
Ah. There’s my answer. I shouldn’t have let the other player come into the scene. “You’re still really busy. This’ll be their conflict.” That would have made them lose the conflict (which of course I was pushing for!). The third character entering in and adding a die of dispo was the factor that tilted things in their favor. So, once a conflict has started, you can’t enter it. You ain’t in the scene. Good to know.