An unobstructed line of sight is necessary for many ranged weapons (although not all, such as trebuchets). So it's a relatively simple matter to create a situation in which someone can't effectively fire at an enemy. Just put something in the way.
Some handy options (roll d20):
- A dense fog.
- One of the shooter's allies.
- A horse-drawn wagon.
- Angry bears.
- A group of schoolchildren. Or nuns. (50% chance of each)
- A sandstorm.
- Two workers carrying a large sheet of glass.
- A herd of alpacas.
- A Saint Patrick's Day parade.
- Stacked barrels of molasses.
- A group of cyclists who will get righteously upset at anyone interfering with the cycle path.
- A rock band shooting a music video.
- Baba Yaga's hut.
- A giant fish tank. Full of sharks.
- An erupting volcano.
- A swirling vortex that leads to another dimension.
- The Great Wall of China.
- A crashed flying saucer.
- An inexplicable wall of blackness.
- A clone of the shooter.
Commentary by memnarch (who has not seen the movie)
All we'd need now is an external shot to see the large guns pointed at the Resistance fleet and someone reporting "stand by" and we'd line up with the end of Episode IV. On a different scale of course; I'm pretty sure the Fulminatrix is still much much smaller than the Death Star mk I. And the Resistance can actually try dodging even if shots get fired at them; planets aren't known for their unpredictable movements after all. Aaaaand I'm still pretty sure only Allan is going to make it out of this whole immediate fight alive, possibly in a burning X-wing as well. If nothing else, he's got BB-8 in his X-wing and Disney wouldn't off their newest droid mascot that quickly. That would be an Episode IX thing if it ever does happen.
I do think the GM is being unnecessarily a pain here. Sure, it's Pete and it wouldn't be fun if it was easy and all that, but there's more players on this side of the fight than just Pete now. Though perhaps that's also due to the screen-caps not allowing for more behinds-the-scenes, uh, scenes, like the other Resistance ships working to jump to hyperspace, and so it would be difficult to present that in the comic without walls of text. Like the trial that was a comic-only thing; that page worked well as it was placed in a scene transition in the movie. Here, it'd probably disrupt the reading flow too much to have something like that also going on at the same time.
Paige: I climb up to the top deck.
GM: Nix is nixed, motionless on the deck. The bomb release button is loose by his hand.
Paige: I reach for the button.
Suday Bascus: Auto-cannons aimed!
Goneril: An interlude! Forty seconds to full charge!
Captain Canady: Destroy that last bomber!! Sorry, Resistance.
GM: This PIE makes a beeline for the Cobalt Hammer.
[SFX]: Pow! Pow!
Allan: I take it out!
GM: Your line of fire is blocked.
Allan: Fench! Look out!
[SFX]: Pow! Kaboom!
GM: Paige, make a Dex roll at -3.
Paige: That’s a lot to happen in between grabbing the button and pressing it.
GM: Oh, you didn’t say you grabbed it...