For those debating this important roleplaying game rules questions:
You read the face facing the floor, as if gravity had been inverted and the die was simply resting on the ceiling plane.
This follows from the cosmology of Spelljammer, which is the best and last word in how gravity should work in a game universe. (Although of course if the die is sufficiently cocked, you have to reroll. That goes without saying.)
[Reminder: Our guest commentators have not seen Rogue One. Part of the fun is seeing how their untainted impressions re-interpret the movie through the lens of our comic.]
Ah, Sally, Sally, Sally.
You are firing into a melee, without specifying who you're shooting at.
While I have never seen dice stuck in the ceiling, I did once have to locate a die that landed in the middle of a large cluster of potted cacti. Also a domino tile. Also a meeple. Also a Hot Wheels car. I have become very good at extracting cactus needles from my hand.
I highly recommend not playing games in a room with large cacti, by the way.
GM: You find an Imperial shuttle.
K-2SO: You know how to fly these things?
Bodhi: I sure do!
K-2SO: And I sure know how to shoot these weapons! Let's go!
GM: You scan the area and find Cassian and Bria, being chased by troopers.
[SFX]: Pow! Pow! Pow! Pow! Pow!
K-2SO: Ha ha! Take that! And that!
K-2SO: And that!!
[SFX]: Pow! Pow!
GM: I've seen dice on the floor before, but this is the first time I've seen one stuck in the ceiling.