In divorce law, the given reasons for a divorce are known as "grounds." In the past, the only viable grounds were "fault-based," meaning one of the spouses would have to accuse the other of some form of wrongdoing, such as adultery or extreme cruelty.
As the law evolved, states added "no-fault" grounds, which do not require proof of misconduct. Initially, some states would allow a divorce if the spouses remained separated for a certain period of time, typically one year to 18 months. Gradually, many states loosened the requirements, permitting divorce for reasons such as "irreconcilable differences," which is the classic no-fault ground for divorce and basically means the marriage is broken and can't be fixed.
Unlike most other states, Oregon has abolished fault-based divorce. Under the law, the courts will grant a no-fault divorce when "irreconcilable differences" have caused the "irremediable breakdown" of the marriage.
However, there are three other permissible grounds for divorce in Oregon. These don't relate to what happened during the marriage, but rather concern the conditions under which the marriage took place. The first is where a spouse hadn't yet reached the legal age to marry. The second involves spouses having lacked sufficient understanding to truly consent to the marriage. The third arises when a spouse agreed to the marriage as a result of force or fraud.
As to the first, most—if not all—states have some age requirement for marriage. In Oregon, it's 18 years old, although a 17-year-old can marry with the consent of a parent or guardian.
Regarding a lack of sufficient understanding, this can come about if a spouse was mentally incompetent when the marriage took place, or perhaps so impaired by alcohol or drugs as to be unable to comprehend the consequences of what was happening.
Agreeing to marry because of force, such as someone threatening you, doesn't rise to the level of true consent. Likewise if your spouse defrauded you, as might be the case when that spouse claimed never to have been married before, although that's a lie.
Note, however, that if a spouse ratifies (goes along with) the marriage after any of the above three deficiencies is discovered and/or cured, that deficiency is no longer a valid ground for divorce. For example, the underage spouse remains married after reaching the legal age, or a defrauded spouse stays in the relationship after learning the truth.
Under Oregon law, there are two scenarios in which a judge will allow a spouse to present evidence of fault. The first relates to child custody. The law requires judges to always act in the best interests of the child. So let's say one of the spouses has a serious, untreated alcohol or drug addiction. Obviously the court needs to know about this when determining custody and parenting time (visitation).
A court will also permit a spouse to discuss fault when that information is needed to prove the existence of irreconcilable differences. Proving irreconcilable differences is often a low bar, but you still have to convince the court that the condition exists. It may seem like skewed logic—talking about fault to prove a no-fault ground for divorce. But if something like evidence of spousal abuse is the only way to show the court that the marriage is irretrievably broken, so be it.
You should be aware that Oregon law specifically provides that a judge can't take fault into consideration when determining spousal support (alimony) or division of marital property.
A spouse can file for divorce immediately in Oregon if the marriage took place in the state, either spouse currently resides in the state, and the grounds for divorce are:
For any other ground for divorce, or if the marriage didn't take place in Oregon, in order to start divorce proceedings either spouse must reside in the state continuously for the six month period before the divorce is filed.
Divorce can be a complex process. Be sure to consult with a knowledgeable and reputable divorce lawyer before taking action.