Alma Family Law Lawyer, New York

Consensual sexual relations by a married person with someone other than his or her spouse. In many states, adultery is technically a crime, though people are rarely prosecuted for it. In states that have retained fault grounds for divorce, adultery is always sufficient grounds for a divorce. In addition, some states alter the distribution of property between divorcing spouses in cases of adultery, giving less to the 'cheating' spouse.

A doctrine that grants the spouse least at fault a divorce when both spouses have shown grounds for divorce. It is a response to an old common-law rule that prevented a divorce when both spouses were at fault.

Secret cooperation between two people in order to fool another. Collusion was often practiced by couples before no-fault divorce in order to make up a grounds for divorce (such as adultery). By fabricating a permitted reason for divorce, colluding couples hoped to trick a judge into granting their freedom from the marriage. But a spouse accused of wrongdoing who later changed his or her mind about the divorce could expose the collusion to prevent the divorce from going through.

Differences between spouses that are considered sufficiently severe to make married life together more or less impossible. In a number of states, irreconcilable differences is the accepted ground for a no-fault divorce. As a practical matter, courts seldom, if ever, inquire into what the differences actually are, and routinely grant a divorce as long as the party seeking the divorce says the couple has irreconcilable differences. Compare incompatibility; irremediable breakdown.

An arrangement by which parents who do not live together share the upbringing of a child. Joint custody can be joint legal custody (in which both parents have a say in decisions affecting the child) joint physical custody (in which the child spends a significant amount of time with both parents) or, very rarely, both.

A legal principle, followed by most states, under which assets and earnings acquired during marriage are divided equitably (fairly) at divorce. In theory, equitable means equal, but in practice it often means that the higher wage earner gets two-thirds to the lower wage earner's one-third. If a spouse obtains a fault divorce, the 'guilty' spouse may receive less than his equitable share upon divorce.

The legal termination of marriage. All states require a spouse to identify a legal reason for requesting a divorce when that spouse files the divorce papers with the court. These reasons are referred to as grounds for a divorce.