This document outlines the essential and legal rules for a valid consideration in a contract. It defines consideration as something given in exchange for something received, or a quid pro quo. There are several rules for consideration to be valid: it must move at the desire of the promisor, it can move from the promisee or third party, it can be past, present or future, it need not be adequate but must be real, it must be lawful, it cannot be something the promisor is already obligated to do, and it can be positive or negative. Examples are provided to illustrate each rule.