In Ohio we have several grounds for divorce, one of which is “incompatibility,” which is a no-fault ground. So, with incompatibility, both parties have to agree. If a complaint for divorce is filed, typically attorneys will include three grounds for divorce: incompatibility, gross neglect of duty, and extreme cruelty? There is a technical reason as to why an attorney will include the latter two grounds. If the only ground listed is incompatibility, and the opposing party denies it, the complaint fails. So, attorneys will put incompatibility under grounds for divorce, but they will include the other two grounds, in case there is a denial as to the first. If the opposing litigant answers and admits incompatibility, the other two grounds for divorce can then be dropped and do not have to be pursued.
There are additional grounds for divorce, but they are not typically used except in extraordinary circumstances. For instance, you could add adultery. You really don’t need to because that would also fit under extreme cruelty, but that doesn’t mean that some people won’t occasionally want to add adultery.