This question already has an answer here:
Watching the original "Star Wars" ("Ep IV" to anyone who didn't see it in '77) last weekend, it occurred to me that the Stormtroopers -- a highly trained government army -- were very poor shots. Evidenced by the scenes where Han rounds a corner ten feet away from a large group (including the ones he was chasing, so there was no element of surprise), and several other scenes that left me thinking as bad an aim as I am, I could have done better. It's not like a laser gun has a recoil.
Of course the good guys had to live, and the Stormtroopers represented an endless supply of cloned cannon fodder, so it didn't matter how many of them were shot.