Since the publication of Scouting for Boys in 1908, all Scouts and Guides around the world, as well as members of the affiliated Alpha Phi Omega service fraternity, have taken a Scout Promise or oath to live up to ideals of the movement, and subscribed to a Scout Law. The wording of the promise and law have varied slightly over time and among Scouting organizations.
Scout Law Wikipedia
The origin of the Scout Law derives from the parallel and closely connected development of the North American and British youth outdoor programs. When writing Scouting for Boys, General Baden-Powell drew inspiration from the work of Ernest Thompson Seton, who had founded the Woodcraft Indians in Canada and the U.S. in 1902, and later was instrumental in spreading Scouting throughout North America. Baden-Powell, on encouragement from Seton in 1904, began forming his Boy Scouts in England. Seton's laws in his 1907 Woodcraft guide (The Birch-Bark Roll) seem unrelated to the Scout Law, being more a list of practical injunctions (Seton pp. 12–13, ee.gg., "Don't rebel," "Don't kindle a wild fire," etc.) than the affirmative, high-minded ideals of the eventual Scouting version. Still, in this primitive form was the source of the idea of a set of codes.
The first list resembling the current form appeared the following year in Baden-Powell's 1908 Scouting for Boys. It is so far unclear to what degree Seton and Baden-Powell collaborated in developing the nine essential points common to nearly all worldwide Scouting programs. The Boy Scouts of America's 1910 version was virtually identical to the original nine British points of 1908, and the BSA's Handbook for Boys (1911), Seton's admixture of Scouting for Boys and his own Woodcraft guides, uses these nine. By 1912 Seton's The Book of Woodcraft (pp. 20–47) studied the qualities of Native American Indians using a list identical to the full 12 points of the 1911 U.S. Scout Law, only in reverse order, indicating the parallel development of the two manuscripts. Similarly, Seton's formulation years later of a 12-point Woodcraft law was much closer to the current U.S. Scout Law and even more elaborate (cf. his Fourfold Fire and Sandpainting of the Fire in Woodland Tales). Somewhere during this period, Scouting programs in the British Isles and colonies added a 10th point regarding spiritual and bodily cleanliness similar to Seton's 11th point.
According to the original U.S. handbook (Seton and Baden-Powell 1911, p. 31), which elaborated on the British version, the founders drew inspiration for the Scout Law from the Bushido code of the Japanese Samurai (Baden-Powell and Seton), laws of honor of the American Indians (Seton), the code of chivalry of European knights (Baden-Powell), and the Zulu fighters Baden-Powell had fought against (Baden-Powell).
The original Scout law appeared with the publication of Scouting for Boys in 1908 and is as follows (sic, capitalization, numbering, etc. by Baden-Powell):
These were written for the Scouts in the whole world, yet of course firstly focused on Scouting in the United Kingdom. As other groups started up Scouting organizations (often in other countries), each modified the laws, for instance 'loyal to the King' would be replaced by the equivalent text appropriate for each country.
During the years, Baden-Powell himself edited the text numerous times, notably in 1911 adding:A SCOUT IS CLEAN IN THOUGHT, WORD AND DEED. Decent Scouts look down upon silly youths who talk dirt, and they do not let themselves give way to temptation, either to talk it or to do anything dirty. A Scout is pure, and clean-minded, and manly.
A version of the Guide law, hand-written by Baden-Powell is displayed at Foxlease.