I think the concept is really great. I see a little flaw though: once you get a weapon you like, there is no incentive for you to continue rolling. What you could do is make it so that each weapon has a limit on its usage equal to the number on the dice. Once every use is consumed, the die will roll automatically. The cool thing is that you can balance things out by putting the strongest weapons on the lowest numbers, like a grenade launcher on 1, a shotgun on 2, etc. I hope you'll take some time to improve this prototype, it's promising!