What is the ruling on someone who judges according to man-made laws; although he believes that the legislation of Allaah The Almighty is best, he can do nothing about it?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

Judging  according to man-made laws,  in spite of conceding that the  laws revealed by  Allaah The Almighty are the only  valid laws,  is considered a  major sin. This is because  judging must be  according to the legislation of Allaah The Almighty.

Allaah The Almighty Says (what means):

•        {The decision is only for Allaah. He relates the truth, and He is the best of deciders."} [Quran 6:57]

•        {And in anything over which you disagree - its ruling is [to be referred] to Allah.} [Quran 42:10]

In certain cases, doing so does not dismiss a Muslim from the fold of Islam, unless he believes that it is correct to judge according to man-made laws.

If you mean by “he can do nothing about it,”  that he is coerced to do so, a coerced person is not considered sinful provided he is under a serious threat, such as a death threat on the part of a group that is known to be serious and able to carry out this threat.

It was narrated, on the authority of Abu Tharr that the Prophet, sallallaahu ‘alayhi wa sallam, said that Allaah The Almighty does not count as sins the errors that  Muslims commit unintentionally, forgetfully or under coercion. [Ibn Maajah]

Allaah Knows best.