A hopper for a paintboll gun is disclosed. The hopper is a gravity feed hopper and has a lower profile than those in the previous art. The hopper fits closely to the profile of the paintball gun and may have multiple chambers along with unidirectional gates to control the flow between chambers and within chambers as well. This invention may take the form of a hopper mounted onto a previous type of paintboll gun as an aftermarket add-on or it may be built into the paintball gun itself as part of its construction.