Sport Stacking (also known as cup stacking or speed stacking) is an individual and team sport that involves stacking specialized plastic cups in specific sequences in as little time as possible. The governing body setting the rules is the WSSA (World Sport Stacking Association). Participants of sport stacking stack cups in pre-determined sequences, competing against the clock or another player. Sequences are usually pyramids of three, six, or ten cups.
Sport stacking is done with specially designed plastic cups, made to prevent sticking to one another and with holes in the bottom to allow air to pass through quickly when stacking. They are designed with ribs reinforcing a ledge inside to keep them slightly apart when nested, so they can be quickly separated.
One can purchase the specifically designed stacking mats, or simply called stack mats, which are mats connected to a sensitive timer. They are used for official tournament timing, casual play timing, or practice timing.
Special weighted training cups are also available. These heavier cups are made of metal and are to be used directly before competitions. The added weight is supposed to make the regular cups feel lighter, allowing the stacker to stack faster in competition.