In contract law, a default rule is a rule which courts imply in agreements when the parties are silent on the matter. For example, there is a default rule in employment contracts that the employee can be fired at any time for any reason. Therefore, if the employment contract doesn't mention firing, the default rule applies and the employee can be fired at any time. If the contract does mention firing, this trumps the default rule and whatever terms they agree to will be binding. The rationale for default rules is they save people who prepare contracts from having to include tons of unnecessary and redundant terms. However, the hidden nature of default rules can be invidious when one party is less sophisticated than the other and does not know the default, and some are controversial for that reason. | 
