How many rules are there for modern soccer?
Laws of the Game (association football)
The actual law book had long contained 50 pages more of material, organized in numerous sections, that included many diagrams but were not officially part of the main 17 laws. In 2007, many of these additional sections along with much of the material from the FIFA Questions and Answers (Q&A), were restructured and put into a new "Additional Instructions and Guidelines for the Referee" section. In the 2016/2017 revision of the Laws, the material from this section was folded into the Laws themselves.
Indoor soccer
Indoor soccer has different regulations from other versions of association football designed for indoor play, such as futsal and five-a-side football. Unlike futsal, which is played on wooden or ceramic surfaces, indoor soccer is played on synthetic turf (or, in the case of the British Masters Football variety, synthetic carpet). Indoor soccer courts are delimited by walls instead of lines, and there are no player throw-ins.
FIFA, the international body that oversees international association football competitions, does not sanction the synthetic turf version of indoor soccer, having developed its own code of indoor football (which they refer to as futsal).