The Ancient and Accepted Scottish Rite of Freemasonry, commonly known as simply the Scottish Rite, is one of several Rites of the worldwide fraternity known as Freemasonry. A rite is a series of progressive degrees that are conferred by various Masonic organizations or bodies, each of which operates under the control of its own central authority. In the Scottish Rite, the central authority is called a Supreme Council.

The thirty-three degrees of the Scottish Rite are conferred by several controlling bodies. The first of these is the Blue Lodge which confers the Entered Apprentice, Fellowcraft, and Master Mason degrees. Blue lodges operate under the authority of Grand Lodges, not the Scottish Rite.

The Scottish Rite is one of the appendant bodies of Freemasonry that a Master Mason may join for further exposure to the principles of Freemasonry. In the United States, the Scottish Rite is officially recognized by the Grand Lodges as an extension of the degrees of Freemasonry. The Scottish Rite builds upon the ethical teachings and philosophy offered in the craft lodge, or Blue Lodge, through dramatic presentation of the individual degrees.

(portions of this introduction taken from Wikipedia)