If you're going to bluff and people start asking questions, the important thing is to have an answer quickly and confidently. It doesn't matter so much what the answer is; what's crucial is that you don't hesitate, or go "um... er..." for a few seconds first, or give your answer the uncertain inflection of a question.
Just say whatever the first thing that comes into your head is, and say it with conviction, as though you absolutely believe it's true, and anyone who questions you must be stupid. Do this well enough, and the people questioning your bluff will start to question their own assumptions, and let you get away with anything, because you're clearly operating at a level they can't fully comprehend.
Commentary by memnarch (who has not seen the movie)
Perhaps I'd be smarter than Random Officer here, but I don't think I'd fall for this bluff. Trooper Finn doesn't look like he's got a camera on him and it's only the two of them walking. I guess there could be security cameras pointed around the hangar bay, but then a recreation shouldn't be necessary.
Though I suppose technically R. Officer here didn't precisely believe the story either. They just provided a different story that seems almost just as silly. Perhaps it's just a way to not show their suspicions and to go get backup before confronting Poe and Finn. The GM hasn't usually been that sneaky from what I remember, and Sally and Ben never specified that they told their underlings about the escape/release plan. So with that in mind, it should just be business as usual for dealing with prisoners, and this could be a great way to throw in some difficulties for Team Evil.
If Phasma's using prisoners for her own amusement though, that's just another checkmark in the confirmation box for the "Is the First Order completely Evil?" question. I wonder how Finn is going to react to that. Torturing prisoners I can see an argument being made that it's for the benefit of the many to try and get valuable information, but prisoner Wookiee-grams... probably less so since Wookiee-grams seem to only be sent to parties or beings of questionable taste.
Commentary by Keybounce (who has not seen the movie)
We have Wookiee-grams again. It's almost like they are the solution to any problem. Anything involving prisoners seems to involve Wookiee-grams.
Carefully paying attention to the distance walked by the people in the background, there's only a few frames of time here. And these few frames of time clearly don't take any time because there's a huge amount of conversation happening in only a few frames. After all, talking is a free action. (Never mind that if you read the rules carefully, it will actually say that you only get a reasonable amount of free actions, not unlimited amounts of free actions.)
Now, why does it feel like the white troopers are just marching around in circles? One group moving in one direction in the foreground, another group moving in a different direction in the background. Is this their form of exercise? Are they doing laps? Or is it like an RTS where they are on patrol because deep inside this giant space ball there is a giant amount of unused space where the Rebels are hiding and they need to be protected from the attack coming from inside the house ship.
For that matter, why is the prisoner doing the talking? Why isn't the trooper explaining? That's gotta raise some questions. For the officers to not go "this is wrong" would require... well, that whole deduction—nothing wrong with the prisoner answering, the conclusion of a Wookiee-gram—that's worse than rolling a single 1. That would require that all five officers think this is OK. The odds of that have to be, what, a million to one? :-)
Possible title: S. Cape Clause
Transcript
Officer: Trooper! Why are you walking this valuable prisoner through the hangar?
Poe: He caught me trying to escape.
Officer: So... why are you walking away from the detention block?
Poe: We’re recreating the crime, for my trial. Smile for the camera.
GM: Roll for Bluff.
[SFX]: roll
Poe: 13!
GM: <roll>
Officer: A likely story. I know what you’re really up to.
Finn: You do?
Officer: Phasma’s using prisoners for Wookiee-grams again, isn’t she?