A fault divorce may be granted when the required grounds are present and at least one spouse asks that the divorce be granted on the grounds of fault. Only some states allow fault divorces. (Find out whether your state allows fault divorces in Nolo's article collection Divorce in Your State.)
The traditional fault grounds are:
Why choose a fault divorce? Some people don't want to wait out the period of separation required by their state's law for a no fault divorce. And, in some states, a spouse who proves the other's fault may receive a greater share of the marital property or more alimony.
What if both spouses are at fault? When both parties have shown grounds for divorce, the court will grant a divorce to the spouse who is least at fault under a doctrine called "comparative rectitude." Years ago, when both parties were at fault, neither was entitled to a divorce. The absurdity of this result gave rise to the concept of comparative rectitude.