Japanese film if I recall correctly. A bunch of kids are sent to an island to fight to the death. The weaker/less intelligent children are given advanced weapons, such as guns. Moving up the totem pole, the stronger kids are given worse weapons, knives and clubs and the like. Some of my details are off, but you get the gist…
Sounds like Battle Royale. I haven’t seen the movie, but what you described closely resembles the book.
You’re welcome. 
Yes! Battle Royale… great fookin’ movie and better book 