Sports all of many kinds has existed across timelines and realities in many forms from the simple to the unfathomably complex.
The Portllflliaxx of the Transitive Continua play an extremely complicated sport, roughly described as a combination of the board game Go, Cricket, Team Handball and Synchronised Aerial Acrobatics. Its combination of automatic scoring and adjudicated results make it difficult for outsiders to understand. A typical test match can last several lifetimes and cross multiple realities and universes.
On the other end of the scale is the game of Po, played by the residents of the one-dimensional Pointillist Plane. The first player to place a slice of one-dimensional space in front of itself wins. While multiple players can compete, the most popular version among pointillions is the solitaire version.
However in an attempt to create a unified sport, the Ecumenical Sporting Council was created to reconcile all variants of sport into one unified set of rules. The rules were set by the council and approved by the founders at a trans-dimensional polygon the cut through most universes at a more or less convenient angle. Because we know where the rules were set it is, unfortunately, impossible to know when.
However these rules are followed by all organizations governed by the FSL.