What are the cases of divorce that do not take effect, especially conditional divorce, and what is meant by intention in that?

For a divorce to be valid, it must be issued by a person of sound legal capacity, meaning one who is sane, adult, and acting willingly. Thus, a divorce pronounced by a child, an insane person, or someone under duress is not valid.

There are varying rulings regarding the validity of divorce pronounced by someone in a state of intoxication, anger, or under the influence of magic. Regarding intoxication, the majority of jurists hold that the divorce of an intoxicated person is valid, because they willingly caused the removal of their own sanity.

As for conditional divorce, if the husband intended to enact the divorce upon the fulfillment of the condition, then the divorce occurs without dispute. However, if the intention was merely to urge or threaten, the majority of scholars hold that it occurs. While Sheikh al-Islam Ibn Taymiyyah and a group of scholars are of the opinion that it does not occur, and the person must offer an expiation for breaking an oath, because "Indeed, every person will have what he intended."