Gambling disorder in court decisions reaffirms the importance of evidence and good faith in claims against betting platforms.
The exponential growth of online sports betting in Brazil has brought about a concerning legal phenomenon: the proliferation of lawsuits invoking gambling disorder, even in the absence of an actual diagnosis (ICD-11: 6C50), as grounds for invalidating valid legal transactions and seeking full reimbursement of amounts wagered. Although gambling disorder is a public health issue that requires the attention of health authorities and regulated-market operators, the opportunistic use of this “diagnosis” in Civil Litigation deserves critical consideration from the legal community.
Against this backdrop, the judgment rendered by the court of the 1st Civil Court of São José de Ribamar, State of Maranhão, in Case No. 0801906-28.2026.8.10.0001, authored by Judge Ângelo Antônio Alencar dos Santos, constitutes a relevant precedent by dismissing, on the merits, the claims for annulment and reimbursement brought against the bet365 platform (HS do Brasil Ltda.).
The lawsuit was filed by a bettor who claimed to suffer from gambling disorder, arguing that such psychiatric condition impaired his ability to exercise control and self-determination in connection with betting activities. The plaintiff sought the absolute nullity of the legal transactions entered into with the platform, alleging a violation of Article 26, item VI, of Law No. 14,790/2023, as well as full reimbursement of the amounts lost, together with compensation for emotional distress.
Gambling Disorder Diagnosis and Civil Capacity
In its defense, the defendant platform argued that the contracts were valid, asserting that the plaintiff had full civil capacity at the time the bets were placed, that he had not formally notified the platform of his condition, and that the platform had strictly complied with the rules on “responsible gambling” and the prevention of gambling-related disorders. Accordingly, the defendant could not be held liable for risks inherent in aleatory contracts.
When analyzing the merits, the judge correctly held that civil capacity is the rule under the Brazilian legal system (Article 1 of the Civil Code) and that a diagnosis of gambling disorder, standing alone, is not sufficient to eliminate an individual’s ability to exercise discernment in civil life, nor does it automatically render the legal transactions entered into by that individual null and void.
For the annulment of such acts to be considered, there would have to be strong evidence that, at the exact time the bets were placed, the plaintiff was deprived of his critical judgment. Although medically relevant for therapeutic purposes, a medical report does not replace the need for a court-ordered interdiction or specific expert evidence attesting to the individual’s incapacity at the time of contracting.
Responsible Gambling and the Duties of Betting Platforms
The decision also recognized that the documentary evidence demonstrated that the defendant platform made “responsible gambling” tools available in a clear and accessible manner, including deposit limits, time limits and a self-exclusion option. The documents submitted to the court showed that, on several occasions, the plaintiff had access to and interacted with his account settings, undermining the argument that the platform had acted negligently or induced the plaintiff’s gambling disorder.
Objective Good Faith and the Prohibition Against Inconsistent Conduct
One of the most relevant aspects of the judgment lies in the finding of a clear violation of the principle of objective good faith and venire contra factum proprium (the prohibition against inconsistent conduct).
The court observed that the plaintiff’s claim, by seeking the annulment only of the bets that resulted in losses, constituted inconsistent conduct. This was because the plaintiff sought to retain the benefits of any previous winnings while avoiding the burden of the losses and transferring the risks of his activity to the defendant.
The judgment also emphasized that an allegation of gambling disorder, without prior and formal notice to the platform—which did not occur in this case—cannot be used as a means of annulling financial losses after unfavorable results have occurred.
Sports Betting and Civil Liability
The judge stated emphatically that the Judiciary, under the pretext of consumer protection, cannot substitute an individual’s will or guarantee the financial outcome of aleatory contracts. Betting activities, when conducted by a legally authorized company, do not, in and of themselves, constitute an unlawful act.
The decision is particularly significant at a time when the Brazilian Judiciary is being overwhelmed by lawsuits that follow a concerning litigation pattern: bettors who, after accumulating losses, obtain medical reports diagnosing gambling disorder and file claims seeking full reimbursement of the amounts wagered.
This represents a form of abusive litigation that, under the pretext of invoking health protection, in fact seeks to transfer the losses arising from a risk-based activity that was voluntarily undertaken.
Gambling Disorder as a Public Health Issue
Gambling disorder is a public health issue that deserves serious and multidisciplinary treatment. Precisely for this reason, its trivialization in lawsuits of an exclusively financial nature does a disservice to those who genuinely suffer from the disorder and require therapeutic support, rather than judicial relief to recover lost bets.
The indiscriminate use of an alleged diagnosis as a litigation strategy to reverse losses arising from aleatory contracts trivializes a serious medical condition and undermines the credibility of individuals who genuinely require protection.
Conclusions of the Court Decision on Gambling Disorder
The judgment rendered in Case No. 0801906-28.2026.8.10.0001 (Court of Justice of the State of Maranhão) represents a relevant contribution to the development of a balanced body of case law on the subject by reaffirming that:
- a diagnosis of gambling disorder does not automatically render legal transactions null and void;
- evidence of incapacity must be contemporaneous with the challenged act;
- platforms that comply with their regulatory duties regarding responsible gambling cannot be held liable for the user’s free choice; and
- the principle of objective good faith prevents bettors from selectively seeking to annul only unfavorable contracts.
It is hoped that decisions such as this one will serve as guidance for the careful examination of these claims, preserving the seriousness of the debate on gambling disorder as a public health issue while, at the same time, preventing the Judiciary from being used as a tool to recover amounts freely wagered by individuals who fail to demonstrate, in the proceedings, any actual impairment of their civil capacity.
Article initially published in the Espaço Jurídico column of SBC Notícias Brasil. Written by Camille Araki and Camila Fernandes, respectively, partner and associate in the Litigation practice.
