1 Will: I fireball the trogs! 13 to hit, right?
1 Lucas: It’s an automatic area effect; save versus spells for half damage.
2 Lucas: Does nobody know the rules but me?
2 Mike: Roll 5d6 for damage, Will.
3 SFX: scatter!!!
4 Will: The dice went all over the floor!
4 Lucas: That's the most realistic thing that's happened all night!

Sorry, one more round of D&D nitpickery. In the TV show, Will says he needs to roll 13 to hit The Demogorgon with his fireball spell. However fireball doesn't require a hit roll - it automatically hits any creature caught within its area of effect.

Including any allies, which is frequently the source of much hilarity in games. Almost as much hilarity as accidentally throwing the dice on the floor, which is definitely one thing the TV show got right.