Sports contracts work similarly to other employment contracts, compensating athletes for their services. Agents negotiate contracts on behalf of athletes, working with lawyers familiar with their client's market value compared to peers. While not required, most athletes hire agents and lawyers for better representation and focus on their career. Contracts without agents are called personal services contracts that can't be transferred, since an athlete's skill is unique. Standard contracts allow teams to assign a player's contract, but popular players can negotiate no-trade clauses preventing unwanted assignments.