Marriage places two people into a legal relationship with one another. Beyond any societal implications, marrying conveys rights and liabilities to a spouse that are far-reaching. Once married, you may have the right to share in your spouse's income and property, be responsible for theirr debts, have sole authority over your spouse's medical care should they become incapacitated and have the right to inherit in the case of their death. Under the law, none of these rights require additional agreements between the spouses. The marriage is the agreement.

The important legal implications of marriage mean that certain requirements must be met in order to become a married person. Laws generally require that the person be of a certain age (usually 18 years of age or over), and that a license be obtained from a government agency, such as a county clerk. The requirements are simple; however, the obstacles are many. As discussed below, marriages may be invalid or voidable, for many reasons, including incapacity, age, and a current marriage to another person.