Rakshasa marriage is a type, in which the groom fights battles with the bride`s family, overcomes them and carries her away and then persuades her to marry. This is not considered as the right kind of marriage as this is forced marriage.
This was a marriage by capture. Primitive tribes regarded women as prizes of war, part of the plunder in a fair fight. This form was common in many other ancient civilization. It appealed to the warrior instinct of the Kshatriya, and was sometimes practised by them. Hindu scriptures describe this form of marriage as forcible abduction of a maiden from her home, while she cries and weeps, after her kinsmen have been slain or wounded and their house broken. Women, thus, caused many fights and battles in ancient times.
When a girl is forcefully taken and marriage is done, it is also not admitted by learned persons and is not religious.