On May 7, the Guardian Games will hold its closing ceremonies and a victor will be announced after all the points have been tallied. Players can use all the medals they've earned over the course of the Games to earn rewards like weapons, shaders, and emblems. But the medals also symbolize a class's overall standing. When you turn them in, they are used to improve your rank and determine the victor. 

Keep in mind that Bungie, Destiny 2's developer, has implemented a new system for this year's Guardian Games to make up for the uneven class sizes. At the end of each week, the last ranking class gets a 10 percent bonus to its medal count. This also helps keep things competitive and all the teams on their toes.