The thesis of this research project is to demonstrate the existence of an incipient philosophy for the playing rules of Gaelic games as examples of invasive body-contact games generally. This philosophy may assist those who make the rules of such games to formulate enhanced sets of playing rules. Improved sets of playing rules may enable the game to be more readily understood, played and controlled by match officials. In turn, this will be of direct benefit to the cultivation and preservation of the games, and will assist compliance with this basic aim of the GAA. Chapter One states the needs for and the limitations of the scope of this research. The history of the philosophy of sport is traced to show its novelty. The existence of a philosophy for legislation in games is asserted by examining the areas of knowledge or components of which it is comprised. Chapter Two examines games from a philosophical perspective, and then sets out the three sections into which all such sets of rules can be divided, before examining a modus operandi for rule formulation. Chapter Three illustrates the principles of play common to such games, then lists and examines the function of rules. The characteristics of rules are listed and examined in detail. It was shown that these characteristics which have much in common with Fuller’s “principles of legality” facilitate formulation of user friendly rules. Chapter Four makes the case that a simple format of presentation enhances ease of learning. It traces the steps taken to develop a universal format, and evaluates this simple method of presentation. Chapter Five discusses the importance, impact and interaction between the law on the content and formulation of the playing rules of these games. This chapter pays particular attention to the tort of negligence with respect to games, and examines important parts of the network of the duty of care inherent in games and their rules. Chapter Six examines the past and present process of rule making in the GAA Chapter Seven argues that a philosophy of legislation can produce enhanced playing rules. After consideration of the foregoing, the playing rules for both games were redrafted by reference to three objective criteria the rules must be (I) easy to read, (n) easy to remember and (m) easy to apply Appendix 1 is a collection of all available sets of playing rules for Gaelic football and hurling. Appendix 2 contains a comparative analysis of the rules of play from 1884 to 1999. This analysis identifies and assesses the philosophical contents of these rules. This Appendix also comprises the early rules of other invasive body-contact games for comparative purposes.