Lucky Hit and Crit mechanics questions

[Shlean]

Can your shot be both a crit and a lucky hit?
Is the Lucky hit damage multiplier always the same for weapons or is it the same as the critical multiplier?
If not, does the casual shooter scroll, which reduces damage by 20% on non-lucky hits, reduce critical hit damage?

[Strider]

They are two separate mechanics. Crits are when you hit their weak spot dealing increased damage. These are consistent. There is no luck involved with a critical hit.
Lucky shots are purely RNG based and can occur regardless of where you hit the enemy.

As far as I'm aware the two stacks do stack as well. So hitting an enemy in a critical spot while getting a Lucky hit proc will result in a massive burst of damage.

[Snobby Hobo]

They do stack. As Strider said they're separate mechanics that can, if the situation arises, stack for an enormous amount of damage. Lucky shot is applied is a multiplier added to the damage after it was calculated with headshot(critical strike) multiplier in consideration.