Football contracts are legally binding contracts signed by football players when hired to play for a specific football team. Football contracts are often negotiated by sports agents who work on behalf of football players in order to secure the desired terms of a contract. Agents receive a fee or a percentage of the contract for their work negotiating football contracts. Players unions also have input on the specifics of football contracts. Generally, football contracts are signed for a specific amount of time. Usually football contracts are multi year agreements, with a set annual salary that may increase with a player's performance. Football contracts will also usually contain a clause detailing what will occur if a player becomes injured and can not complete his contractually obligated term. In order to reduce the risk of injury to players, football contracts often contain provisions outlawing specific activities, such as motorcycle riding. Players who violate the terms of a football contract may be penalized or suspended or otherwise punished.