The concept of annulment is not at all similar to divorce. Many of us believe that the two are closely related due to the fact that the final result is same, that is, the marriage legally dissolves. The legal procedure and their basis is however different. Annulment of marriage is declaring the marriage to be null and void, ab initio, this basically, means that the marriage is not valid right from the beginning, due to some or the other circumstances, events or facts relating to the marriage. A divorce is however the end of a legal and lawful marriage, that was valid right from the beginning. Thus, from a legal prospective, laws pertaining to annulment and divorce are quite different. These laws in all the states of US are either practiced in the civil courts and, in some cases, are also practiced in the Catholic Church. The annulment state laws do differ from state to state, however the basic principles are the same.
Common Annulment Laws
The common grounds for an annulment process include, lack of capacity to give consent, or fraud, or legal distortion during the marriage. Let's take a look at all the three:
Consent and Capacity to Consent
Every person has a right to get married, however, this right is largely governed by some or the other legal validity, i.e. the person should be able to use the right properly. The term 'capacity' indicates that the person getting married should be of sound mind and constitution while getting married. Often you will come across movies and sitcoms where two characters get drunk and then get married (often, in Las Vegas). Well this kind of marriage can be easily annulled owing to the fact that the people were drunk and did not have a sound constitution to give sufficient consent. A consent from either parties is thus, the basic requisite to get married. Some other conditions influencing the capacity to give consent, is of being sound mind, free from any influence, and it also includes being under some other person's influence.
Fraud and Illegal Faction
The second kind of grounds, is a fraud or illegal faction in the marriage. Though rare, in some cases, marriages like these do take place. For example, forced marriage, use of threat or force during the proceedings, or anything, action, occurrence or event that can be deemed to be a fraud. Fraud may also include, false and intentional misrepresentation or non-disclosure of some important facts about self, or family. Sexuality, diseases, or any other fact affecting the marriage drastically, can be viewed to be fraudulent misrepresentation. In certain cases, such a misrepresentation can also be deemed to be a mistake, or unintentional misrepresentation.
The third ground, is of course distortion in the legal aspects of the marriage. For example, say, a person already married to one person gets married to another, which makes the second marriage a valid case for annulment. The concept of legal distortion is principally valid for marriages that are not legally possible. Another example is marriage to a minor.
Cases have been observed when a combination of all the three grounds of annulment have been observed. It is up to the judge or jury of the court to ascertain whether the said marriage can be annulled or not. The spouses need to prove any of the aforementioned grounds that would, cause the marriage to be void ab initio.
The Catholic Church, in certain cases, can act as a judge for annulment. The jurisdiction is however, quite limited and the annulment is more like a 'soft' and less harsh procedure. This procedure is again limited to grounds such as consent and disclosure. Fraud and intentional misrepresentations are however, strictly dealt with by the court of law.