Morgan's original 1895 rules were far looser than today's: there was no limit on the number of players per side, no cap on how many times a team could touch the ball before returning it, and the net stood at 6 feet 6 inches — far lower than the modern 2.43-meter men's height. The game only gradually acquired the structural rules that give it its modern shape. A three-touch limit per side was adopted in the early 1900s to keep the game moving and prevent one side from stalling, and the six-player, three-front three-back lineup with clockwise rotation became standard by the 1910s to 1920s as organized leagues formalized play.
The net was raised over time as the sport spread beyond casual recreation into competitive play among trained athletes; it reached close to its current 2.43-meter men's height by the 1900s-1910s, well before most of the sport's other modern rules were in place. Attack-line restrictions on back-row players, blocking rules, and the specific fault definitions used today were refined across the twentieth century as national federations and, eventually, the FIVB standardized the rulebook worldwide.
Codifying the game for competition
The United States Volleyball Association (now USA Volleyball) was founded in 1928 to govern the sport domestically and hold a national championship, and the Fédération Internationale de Volleyball (FIVB) was founded in Paris in 1947 to do the same on a global scale. Both organizations played central roles in tightening and unifying the rulebook, work that continues today through periodic FIVB rules-cycle revisions.
Rule changes as a continuous process, not a finished job
It is a mistake to think of the rulebook as having been 'finished' at some point in the early twentieth century; the FIVB still revises its official rules on a multi-year cycle today, and even recent decades have seen major structural changes — the abolition of technical timeouts starting in the 2021-2024 cycle, the introduction of the libero around 1998, and the adoption of rally point scoring in 1999 among them. Volleyball's rulebook, in other words, has never really stopped evolving since Morgan's first, much simpler version in 1895.

