Most states allow spouses seeking a divorce to allege fault in the breakup of the marriage as a basis for the divorce. Alleging the other spouse’s fault—rather than seeking the divorce on no-fault grounds (irreconcilable differences or incompatibility, making the marriage unsustainable)—is generally a basis for requesting the court make an uneven distribution of the marital or community property in favor of the spouse alleging the other’s spouse’s fault.

In states that allow a spouse to seek a divorce on fault grounds, the grounds that may be alleged vary from state to state, but generally include adultery, cruelty, conviction of a felony, family or domestic violence, abandonment, mental illness, and substance abuse (drugs and alcohol). Spouses may also seek a divorce on no-fault grounds in these states.

In no-fault states, a spouse is not allowed to allege fault as grounds for the divorce, and the court is not allowed to consider fault in dividing the marital or community property—but allegations of fault may be considered for other purposes, such as spousal support and child custody. No-fault states include California, Colorado, Florida, Hawaii, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, Oregon, Washington, and Wisconsin. And in some states “incurable insanity” is a no-fault ground for divorce.

The grounds on which a spouse may seek a divorce (fault or no-fault) are usually located in a state’s statutes—often in the family code or domestic relations code.

In Oklahoma, spouses seeking a divorce can file on either fault or no-fault grounds. No-fault divorce is based on incompatibility, which means the marriage is irretrievably broken. However, Oklahoma law also allows for fault-based divorces, with grounds that include adultery, abandonment for one year, fraud, extreme cruelty, habitual drunkenness, gross neglect of duty, imprisonment of the other spouse for the commission of a felony, the procurement of a final divorce decree outside of Oklahoma by a spouse which does not release the other spouse from the obligations of the marriage within Oklahoma, and insanity for a period of five years. When fault is alleged and proven, it can impact the division of marital property, with the possibility of an uneven distribution favoring the non-faulting spouse. Additionally, fault may be considered when determining issues such as spousal support and child custody. It's important to note that while fault can play a role in the divorce proceedings, the presence of no-fault grounds allows for a divorce to be granted without the need to prove wrongdoing by either party.