Sweden is a monarchy and King Carl XVI Gustaf is Sweden's Head of State. The King's duties are mainly of a ceremonial and representative nature. As Head of State the King opens the new session of the Riksdag every autumn.
The Act of Succession determines the order in which the descendents of the present King shall succeed to the Swedish throne. Until the 1970s male descendents always had precedence to the throne. A woman could only become Queen if there were no male alternatives. In 1979, however, it was decided that male and female heirs would have equal rights to the throne.
Read the full-text version of the Act of Succession