Two regimes, one sport: why the distinction between lex ludica and lex sportiva determines who is right before the argument even begins (Part I)

Series: Lex Ludica and Lex Sportiva: the autonomous legal order of international sport
Technical level: High — arbitrators, sports lawyers, academics
Suggested citation: Martínez Cartagena, J.M. (2026). Two regimes, one sport. The Sports Dossier. juanmanuelmartinezc.com/dossier/

When a club appeals to the CAS alleging that the match referee erred by not awarding a penalty in the 89th minute of a decisive match, the tribunal's response is almost always the same: the appeal is admitted, processed, and decided on the merits—and on those merits, the CAS panel declares that it will not intervene. Not because the party lacks standing, nor because the error is implausible. Rather, because that decision belongs to a regulatory regime different from the one CAS is institutionally and functionally empowered to review. Abstention is not an admissibility filter: it is a deliberate choice of legal policy that the tribunal itself exercises over the merits of the case.

That response is not a procedural evasion. It is the most concrete expression of a structural distinction that organizes all of international sports law and which, nevertheless, continues to be confused or ignored with a frequency that costs cases: the distinction between lex ludica and lex sportiva.

The thesis of this article is as follows: the distinction between lex ludica and lex sportiva is not an academic classification of descriptive value. It is an operational legal tool that determines the arbitrator's jurisdiction, the applicable standard of review, the relationship of the sports legal order with national law, and the perimeter within which any argument has any possibility of succeeding. Confusing them is not a minor theoretical error. It is the error that decides a case before it even begins.

This article opens Series 2 of The Sports Dossier by reconstructing this distinction from its foundations: the jurisprudential origin of the category, its technical refinement by doctrine, and its concrete operational consequences for those who litigate or arbitrate in the international sports system.

I. The origin: AEK Athens and lex ludica as a jurisprudential category

The expression lex ludica has a precise origin. It appeared for the first time in the language of the Court of Arbitration for Sport in the award AEK Athens & SK Slavia Praha v. UEFA (CAS 98/200, award of 20 August 1999)^[1], where the panel used it as a technical term to designate the set of unwritten legal principles inherent to sport, constructed by analogy with the lex mercatoria of international trade.

The context of the award was as follows: the panel had to determine whether international sports federations were subject only to their own statutes and internal regulations, or if there existed some superior regulatory body of general scope to which they must also answer. The answer was yes. Transnational sport generated effects in multiple jurisdictions, and this fact imposed compliance with substantive and procedural principles of universal scope. The panel thus identified the existence of general principles of law constructed from a comparative reading of national legal systems—in particular, the prohibition of arbitrary or disproportionate rules—which formed part of an emerging regulatory body applicable independently of any specific regulatory text.

What AEK Athens contributed was not just the name. It was the confirmation that CAS arbitration practice since 1986 had been building this regulatory body without naming it. Matthieu Reeb^[2] would make this explicit in the introduction to the second volume of the Digest of CAS Awards, pointing out retrospectively that the first Digest—compiling awards from 1986 to 1998—had already documented the formation of a lex sportiva through the accumulated arbitral practice of the tribunal. With this, Reeb coined a broader category: the autonomous regulatory corpus of international sport, consolidated in CAS jurisprudence and endowed with a universal vocation.

The problem with that naming—which would become methodologically costly for years—is that it amalgamated under a single label legal phenomena of structurally different natures. It was Ken Foster^[3] who, in 2005, made a decisive advance in the technical refinement of this conceptual architecture.

II. Foster and taxonomy: five categories where there was only one

The starting point of Foster's analysis is an epistemological critique that retains all of its relevance: the term lex sportiva, as it circulated in doctrine and in CAS jurisprudence itself, was an imprecise concept that amalgamated legal currents of a heterogeneous nature. To demonstrate this imprecision, Foster subjected CAS jurisprudence to a systematic analysis and identified within it five distinct legal categories: lex ludica, good governance, procedural fairness, harmonization of standards between international federations, and equitable and individual treatment.

Foster's technical conclusion was that, within this taxonomy, only the harmonization of standards constitutes lex sportiva in the strict sense—understood as a transnational private order built from the customary practice of international sports federations and consolidated through international arbitration. The other categories respond to legal foundations of different origin and nature: not everything CAS does when resolving a sports dispute is lex sportiva, and confusing the specific category with the whole is the source of much of the doctrinal imprecision.

For the purposes of this analysis, what matters is the position Foster reserves for lex ludica within this taxonomy. Lex ludica is not just a description of which rules apply on the field of play. It is the expression of an adjudication model: CAS delimits the matters that enjoy legal immunity and abstains from intervening in them. The fundamental principle underpinning this model—which Foster borrows from Beloff—is the autonomy of sports decision-making bodies and the establishment of what he calls a constitutional balance between courts and federations. The logical structure of this balance is analogous to that of judicial review of the acts of public authorities in national legal orders: the merits of the decision are not reviewed; high standards of irregularity are required to justify intervention; the emphasis is on respecting formally attributed competences and the integrity of sport.

III. Lex ludica: zone of immunity, not a source of law

The lex ludica comprises the constitutive technical rules of each sports discipline: the rules that define what the game is, how it is played, what constitutes a technical infraction, and how the result is calculated. The Laws of the Game of football drawn up by the IFAB, the rules of tennis under the ITF, the athletics regulations under World Athletics. Its defining feature is that they do not regulate legal relationships between people: they regulate the game itself.

Three characteristics define it as an autonomous legal category. First, its immanent origin: the rules of the game do not derive from any authority external to the sports system, but from the consolidated historical practice of each discipline. Second, its technical logic: the offside rule is not interpreted in accordance with general principles of law, but in accordance with the internal rationality of the game they regulate; its meaning is inaccessible from outside the system without specialized knowledge. Third—and decisive—the exceptional nature of its external review.

The most important legal consequence of lex ludica is the immunity of field-of-play decisions from arbitral and judicial review. The canonical formulation of this doctrine was produced by the award issued by the CAS Ad Hoc Division during the Salt Lake City Olympic Games (KOC v. ISU)[^[4]], where the panel enunciated two foundational principles: CAS panels do not review decisions made on the field by officials responsible for applying the rules of the game because, unlike those officials, they have not been selected for their expertise in officiating the specific sport; and for CAS to exceptionally review a field-of-play decision, there must be direct evidence of bad faith, understood as some indication of preference or prejudice toward a particular team or individual.

The philosophical justification was clearly articulated: every participant in a sport where referees make decisions on the field must accept that the referee perceives the incident from a certain position and decides based on what they see; referees make mistakes, just as the players themselves do, and this is an inevitable fact of sporting life; not every mistake is subject to review, and therefore a participant cannot challenge a field decision simply because they disagree with it.

The award Aino-Kaisa Saarinen & Finnish Ski Association v. FIS (CAS 2011), systematized into eight numbered propositions by a panel chaired by Michael Beloff QC, added the most important procedural clarification of the entire line of jurisprudence: CAS's abstention regarding field-of-play decisions is not a matter of jurisdiction, but of arbitral self-restraint. In the award's own words:

The CAS's abstention is not a matter of jurisdiction, but of arbitral self-restraint. (Finnish Ski Association v. FIS, CAS 2011, §38.)^[5]

The procedural consequences of this clarification are of the first order: the appeal is admissible and must be decided on the merits, where CAS declares its abstention. A declaration of lack of jurisdiction is not appropriate. What the tribunal does is not to say that it cannot hear the matter. It says that, while being able to hear it, it chooses not to intervene. That choice is legal policy, not an absence of jurisdiction. And like any legal policy, it has exceptions. Finnish Ski Association specified them: the doctrine yields if it is demonstrated that the decisions were tainted by bias, malice, bad faith, arbitrariness, or legal error. The incorporation of legal error as an autonomous category, alongside the already known ones, was the substantive novelty of this award compared to predecessor awards.

The most recent development of the doctrine comes from the Paris 2024 Olympic Games^[6], where the CAS Ad Hoc Division introduced organizational negligence—not just bad faith—as an exception to qualified immunity. The systemic consequences are potentially considerable: if institutional negligence in managing internal technical review mechanisms enables arbitral review, the perimeter of lex ludica contracts. Subsequent jurisprudence will determine whether Paris 2024 constitutes a lasting turning point or a circumstantial response.

IV. Lex sportiva: the legal order built award by award

The lex sportiva operates on a radically different level. It does not deal with whether the ball crossed the goal line, but with whether a player's contract was terminated with or without just cause, whether a sanction was proportionate, or whether a federation can impose restrictions on the free movement of athletes. Its subject matter is not the game itself, but the legal organization of sport as a social, economic, and institutional phenomenon.

The most solid doctrinal basis for understanding lex sportiva as a verifiable normative phenomenon comes from a tradition that Anglo-Saxon doctrine rarely cites with the precision it deserves: Italian legal institutionalism. Santi Romano, in L'ordinamento giuridico (1918)^[7], formulated the thesis that legal character does not depend exclusively on state recognition, but can emerge from any social formation endowed with organization, regulatory capacity, and effectiveness. Massimo Severo Giannini, in the inaugural article of the Rivista di Diritto Sportivo (1949)^[8], applied this construct to international sport and identified within the sports system the three elements that Romano considered constitutive of any legal order: plurisubjectivity (plurality of subjects), organization, and rule-making. The result was the characterization of sport as a super-state and international legal order whose subjects are natural and legal persons of private law organized in federations with global reach.

What Ken Foster formulated since the early 2000s—and subsequently developed by distinguishing between global sports law, lex sportiva, and lex ludica—can be read as the Anglo-Saxon reconstruction of an intuition that Massimo Severo Giannini had anticipated half a century earlier from Italian institutionalism: organized sport does not operate merely as a collection of scattered private contracts, but as a normative order endowed with its own institutions, rules, procedures, decision-making authorities, and enforcement mechanisms. The categories are different; the underlying legal question is substantially convergent. When a phenomenon can be identified from such distant theoretical traditions—Italian institutional theory and Anglo-Saxon transnational theory—the most precise hypothesis is not to deny its existence, but to explain its nature, its sources, and its limits.

For this reason, when a CAS arbitrator decides on the validity of a clause in a transfer contract, they do not resolve the dispute exclusively from the classic categories of a specific national law. Their analysis starts, first of all, from the applicable sports regulatory framework: federative regulations, the rules of the competition or of the corresponding organization, the contract in dispute, the law chosen by the parties, and the general principles developed by sports arbitral jurisprudence. National law may intervene, depending on the case, as the chosen law, as subsidiary law, as a parameter of validity, or as an external limit of control; but it does not, on its own, exhaust the legal reasoning of the sports arbitrator. Lex sportiva, in this sense, does not displace national law, but neither is it reduced to it.

The position maintained here—coinciding with Franck Latty's thesis^[9]—is that lex sportiva exists as a verifiable normative phenomenon, but its autonomy is functional, not sovereign. It is functional because it allows transnational sport to produce rules, resolve disputes, and generate a certain decisional uniformity beyond national legal systems. But it is not sovereign because its ultimate effectiveness depends, in case of resistance, on its interaction with national law: whether through the recognition of awards, judicial control of minimum guarantees, public policy, competition law, labor law, or national enforcement mechanisms.

A CAS award can produce authority within the sports system, guide the conduct of federations, clubs, and athletes, and even activate internal compliance mechanisms. But when its effectiveness requires coercively affecting the assets of a person or entity outside the sports associative system, lex sportiva must meet national law: it needs recognition and enforcement by national courts, in accordance with the New York Convention of 1958. This dependence does not reveal a conceptual weakness of lex sportiva. It reveals its true nature: a transnational regulatory order, functionally autonomous but not sovereign; capable of producing its own rules and decisions, although in need of the State when coercion ceases to be associative and becomes patrimonial.

V. The operational distinction: four consequences that define a case

Having drawn the conceptual distinction, it is appropriate to extract its concrete legal consequences for the operator of the system. The difference between lex sportiva and lex ludica is not a merely classificatory matter. It can determine how to frame the case, the applicable standard of review, the intensity of arbitral or judicial control and, ultimately, the very outcome of the litigation.

First: the CAS review threshold. CAS hears disputes submitted to its jurisdiction in accordance with the applicable statutes, regulations, or arbitration clauses. However, when the dispute concerns a decision strictly adopted on the field of play—that is, on the immediate application of the rules of the game or technical competition rules by the referee, judge, or sports official—a material limit of review known as the field of play doctrine operates. In those cases, the problem is not always that CAS lacks jurisdiction in the strict sense, but rather that, even while having jurisdiction, it normally abstains from substituting the technical appreciation of the field official, except in exceptional cases of bad faith, manifest arbitrariness, fraud, or serious breach of the minimum guarantees of the sporting process. A lawyer who structures their appeal before CAS as if it were a simple appeal against the technical assessment of the field referee is usually, from the outset, outside the tribunal's actual argumentative field.

Second: the standard of review. Under lex sportiva, CAS can deploy a full review: it examines facts, assesses evidence, interprets regulations, applies general principles, and controls the proportionality of the challenged decisions. Under lex ludica, by contrast, review is exceptional and deferential. A technical decision adopted during the competition is not reviewed simply because it is debatable, erroneous, or controversial. For CAS to intervene, the appellant must demonstrate something qualitatively different: bad faith, manifest arbitrariness, corruption, fraud, undue bias, or an institutional anomaly of such gravity that it prevents the decision from being considered a genuine technical assessment of the game. The difference is not only procedural: it defines the entire argumentative horizon. An argument designed for de novo (full) review is not sufficient, on its own, to overcome a standard of extreme deference.

Third: the relationship with national law. Lex sportiva is exposed to the control of national and supranational law when its decisions affect rights, proprietary obligations, conditions of access to the profession, disciplinary sanctions, economic freedom, due process, or public policy rules. Lex ludica, on the contrary, enjoys a much more intense immunity from external review, precisely because it protects the immediate authority of the game and the stability of the competitive result. Arbitral jurisprudence has recognized that field-of-play decisions cannot ordinarily become subsequent legal disputes, as this would deprive the referee, judge, or sports official of the meaning of their function during the competition. In Finnish Ski Association, CAS addressed this tension when analyzing how far the field of play doctrine could extend, recalling that its justification rests on the need to prevent the game from being permanently interrupted or reopened by subsequent legal appeals.

Fourth: regulatory production and who can change the rules. Lex ludica is produced, as a general rule, by specialized technical bodies that define the rules of the game of a sports discipline, the scoring criteria, the review systems, the validity conditions of a play, or the technical parameters of the competition. Lex sportiva, on the other hand, emerges from a more complex ecosystem: international federations, national associations, disciplinary regulations, codes of ethics, transfer rules of federative and economic rights, internal judicial bodies, CAS and, with increasing intensity, national and supranational courts. Knowing who produces the rule governing the case is not an academic question. It is the starting point for determining what instrument can modify it, who can interpret it, what standard of control applies, and what legal consequences it can produce for the parties.

VI. The field in tension: why Diarra is possible and why the Atlanta ruling is not

The analytical utility of the distinction becomes clearer when contrasted with its extreme cases. In 1996, during the Atlanta Olympic Games, the CAS Ad Hoc Division heard the case Mendy v. Association Internationale de Boxe Amateur (AIBA)^[10]. The boxer had been disqualified for a low blow and argued that the blow was, in fact, lawful. For the panel, the challenged decision belonged to the technical core of the competition: it was an assessment made by the referee and the ringside judges during the fight itself. Therefore, CAS abstained from substituting that assessment, recalling that an arbitral body, situated outside the immediacy of the action, was in a worse position than the officials responsible for applying the rules of the fight in real time. The field-of-play decision remained, in principle, protected by the inherent autonomy of lex ludica.

This abstention, however, does not equate to a metaphysical immunity. Even in the classic formulation of the doctrine, CAS left open the possibility of review in exceptional circumstances: error of law, arbitrariness, malicious intent, or violation of general principles of law. The rule is not that every decision made during the competition is legally untouchable; the rule is that the immediate technical assessment of the game cannot be reopened just because a party believes the referee, judge, or sports official made a mistake. Lex ludica protects the competitive result against the ordinary conversion of the game into litigation.

In 2024, the Court of Justice of the European Union delivered the Diarra judgment—case C-650/22^[11]—and questioned the compatibility of key provisions of the FIFA Regulations on the Status and Transfer of Players with Article 45 TFEU, relating to the free movement of workers, and with Article 101 TFEU, relating to competition law. The intervention was possible—and legally successful—because the object of control was not a technical decision adopted on the field, but a set of federative rules regulating legal relations between players, clubs, and federations: liability for compensation, sporting consequences of breach of contract, and the issuance of the international transfer certificate.

The same CJEU that is not called upon to rule on whether an offside was correctly flagged can declare a transfer regulation incompatible with European law. This asymmetry is not accidental. It is the logical consequence of the structural distinction that this article develops. Lex ludica ultimately protects the integrity of the game as a competitive phenomenon: without certainty that results are produced and stabilized on the field, sport as an autonomous human activity becomes unviable. Lex sportiva protects something else: the legal ordering of institutionalized sport, that is, the relations between clubs, players, federations, leagues, agents, organizers, and other participants in the system. For that reason, it is exposed to the external scrutiny of national and supranational law when it affects fundamental freedoms, proprietary rights, market access, professional conditions, or minimum guarantees of due process.

The Bosman (1995)^[12]–Meca-Medina (2006)^[13]–Diarra (2024)^[14] axis should not be read, therefore, as a sequence of external interventions that destroy the autonomy of sport. It must be read as the demonstration that this autonomy was always functional and conditioned: sufficient to allow sport to build its own regulatory system with real regulatory density, but insufficient to shield this legal order against the law that protects the fundamental freedoms of those who participate in it. Lex sportiva survives each of these rulings—none of them eliminated sport or its regulatory system—but emerges from each with more precise contours and with less margin to invoke sporting specificity as an absolute shield.

The following articles in this series will reconstruct this sequence in detail: how CAS built lex sportiva case by case, and how European supranational law has been drawing its limits from Bosman to Seraing. This article serves a more modest, but necessary, function: to establish the structural distinction without which that sequence is simply unintelligible.

Jurisprudential references

• CAS 98/200, AEK Athens & SK Slavia Praha v. UEFA, award of 20 August 1999.
• CAS, Ad Hoc Division, award M. v. AIBA, Atlanta Olympic Games, 1996.
• CAS, Ad Hoc Division, award Segura v. IAAF, Sydney Olympic Games, 2000 (§17).
• CAS, Ad Hoc Division, award KOC v. ISU, Salt Lake City Olympic Games, 2002.
• CAS 2004/A/704, Yang Tae Young & KOC v. FIG, award of 21 October 2004.
• CAS 2011/A/2671, Finnish Ski Association & Saarinen v. FIS, award of 6 June 2011.
• CAS 2016/A/4643, HSI & O'Connor v. FEI, award of 3 August 2016.
• CJEU, Judgment of 15 December 1995, Case C-415/93, Bosman.
• CJEU, Judgment of 18 July 2006, Case C-519/04 P, Meca-Medina.
• CJEU, Judgment of 4 October 2024, Case C-650/22, Diarra.

Doctrinal references

• Foster, K. (2005). 'Lex Sportiva and Lex Ludica: The Court of Arbitration for Sport's Jurisprudence'. Entertainment and Sports Law Journal, vol. 3, no. 2.
• Foster, K. (2003). 'Is There a Global Sports Law?'. Entertainment and Sports Law Journal, vol. 2, no. 1.
• Giannini, M.S. (1949). 'Prime osservazioni sugli ordinamenti giuridici sportivi'. Rivista di Diritto Sportivo, vol. 1.
• Latty, F. (2007). La lex sportiva: Recherche sur le droit transnational. Martinus Nijhoff Publishers.
• Reeb, M. (ed.) (2002). Digest of CAS Awards II, 1998–2000. Kluwer Law International. [Introduction.]
• Romano, S. (1918). L'ordinamento giuridico. Sansoni (reprint 1946).

1. CAS 98/200, AEK Athens & SK Slavia Praha v. UEFA, award of 20 August 1999. ↩︎
2. Reeb, M. (ed.) (2002). Digest of CAS Awards II, 1998–2000. Kluwer Law International. ↩︎
3. Foster, K. (2005). 'Lex Sportiva and Lex Ludica: The Court of Arbitration for Sport’s Jurisprudence'. Entertainment and Sports Law Journal, vol. 3, no. 2. ↩︎
4. CAS, Ad Hoc Division, award KOC v. ISU, Salt Lake City Olympic Games, 2002. ↩︎
5. CAS 2011/A/2671, Finnish Ski Association & Saarinen v. FIS, award of 6 June 2011, § 38. ↩︎
6. CAS, Ad Hoc Division, awards of the Paris 2024 Olympic Games. ↩︎
7. Romano, S. (1918). L’ordinamento giuridico. Sansoni (reprint 1946). ↩︎
8. Giannini, M.S. (1949). 'Prime osservazioni sugli ordinamenti giuridici sportivi'. Rivista di Diritto Sportivo, vol. 1. ↩︎
9. Latty, F. (2007). La lex sportiva: Recherche sur le droit transnational. Martinus Nijhoff Publishers. ↩︎
10. CAS, Ad Hoc Division, award M. v. AIBA, Atlanta Olympic Games, 1996. ↩︎
11. CJEU, Judgment of 4 October 2024, Case C-650/22, Diarra. ↩︎
12. CJEU, Judgment of 15 December 1995, Case C-415/93, Bosman. ↩︎
13. CJEU, Judgment of 18 July 2006, Case C-519/04 P, Meca-Medina. ↩︎
14. Ibid (Diarra, n 11). ↩︎