Discovery Rights is an MLS mechanism that allows a team to claim exclusive negotiating rights with a player not currently signed to an MLS club. Once a team files a discovery claim on a player, other MLS teams cannot negotiate with that player unless they trade for the discovery rights.
Each team can hold discovery rights on a limited number of international players at any given time. This system was designed to prevent bidding wars between MLS clubs for international talent, but it has been controversial. Critics argue it limits competition and can prevent players from signing with the team that values them most. The league has modified discovery rules over time, and the mechanism plays a less prominent role than it once did as MLS has evolved its approach to international player acquisition.