Generally, the defenses in a fault divorce are jurisdiction and the fault ground may be different than the lay conception of it.
Beginning with California in 1971, states began to permit no-fault divorce, and by the end of the 1970s, all but two states had some version of no-fault. Compared to fault divorce laws, many of which dated from the 19th century, no-fault was an idea whose time had come. However, in many jurisdictions, lawmakers added no-fault to the established divorce law, so fault divorce is still possible in more than 30 states.
In a few states, marital misconduct such as adultery works to the victim’s advantage in the assets is treated more seriously.
The most common form of economic misconduct is dissipation of marital assets. In the distribution of the marital majority of jurisdictions consider marital misconduct only when it has an economic impact on the marital estate. For example, the adulterous conduct of a man may be irrelevant, but the fact that he squandered marital funds at the racetrack with his girlfriend may be considered. A few jurisdictions consider the marital misconduct even when its impact is noneconomic or only slightly so.
Compared to uncontested divorces, the legal strategy behind fault divorce is much more complex, so a fault divorce means a party will need a lawyer. For example, fault divorces often invite a consideration of leverage factors. Fault divorce is generally more expensive because it may entail a subpoena. If there are questions about hidden or secreted assets, expert witnesses such as forensic accountants enter the picture. According to one source, more than 90 percent of the court cases settle before the trial, and with good reason.
In most states, alleging and even proving fault does not work to the advantage of the spousal support.
Even when a party has grounds for a fault divorce, many spouses today choose the no-fault route because it is easier and simpler. Some aggrieved spouses, however, may be tempted to use fault in retribution or as a means of vindication. Such strategy is often ill advised. Most judges have "heard it all before," and they are unmoved.
Until the 1970s, almost all jurisdictions required proof of alimony and some consider fault in determining property distribution, the decision to use it in place of no-fault requires legal advice.
See also No-Fault Divorce.