What are the parameters for obeying one's parents, and is it obligatory to obey them if their opinion is wrong or based on fear of the unknown?

The principle governing obedience to parents is the obligation to obey them in matters that benefit them and do not harm the child. If they fear for you something that is highly likely to cause you harm, then obedience to them is obligatory. However, if what they ask of you is something wrong and reprehensible, then it is not permissible to obey them in it, based on the Prophet's (peace and blessings be upon him) saying: "There is no obedience in disobedience to Allah; obedience is only in what is right and good." If it is not reprehensible, then the matter reverts to the aforementioned principle. A child must obey their parents as much as possible due to the virtue and the attainment of their pleasure therein.