Implied Contract

An implied contract is a contract that is not in writing and is lawful because of the actions of the parties and the circumstances they are in.

The old saying comes to mind: "If it walks like a duck, smells like a duck, and sounds like a duck, then it must be a duck." Acting as something can mean you are that thing. For example, at a restaurant, once a patron sits down and orders, it is implied he or she will eat, and he or she will pay for the food.