GLI-19 vs GLI-33: Choosing the Right Standard for Your Certification Path

Why Standard Selection Is a Strategic Decision

When a supplier or operator enters the certification queue with Gaming Laboratories International (GLI), one of the first consequential choices is which technical standard governs the engagement. For interactive and sports betting products, this typically means choosing between GLI-19: Standards for Interactive Gaming Systems (currently v3.0) and GLI-33: Standards for Event Wagering Systems (currently v1.1, revised May 14, 2019). The distinction is not cosmetic. Each standard addresses a materially different system architecture, set of risk profiles, and regulatory expectation. Selecting the wrong standard at the outset is not merely an administrative error; it can invalidate months of test preparation and delay market entry.

This article provides compliance professionals with a structured comparison of both standards, covering scope delineation, key technical chapters, overlap zones, jurisdictional adoption patterns, and the operational decision points that should inform a certification strategy. It assumes familiarity with GLI’s testing and certification process; readers requiring a foundational overview of independent testing laboratory (ITL) processes should consult GLI’s GLI Product Certification Scheme (PC-QS-011) before proceeding.

GLI-19 Interactive Gaming Systems: Scope and Architecture

GLI-19 v3.0 is GLI’s primary standard for online and interactive gaming platforms. Its scope encompasses the full stack of a conventional online casino operation: server-side game logic, random number generation (RNG) and its statistical validation, game client presentation, account management systems, transaction processing, and responsible gambling controls embedded at the system level. The standard is used as a baseline or direct requirement by a wide range of regulated jurisdictions, including markets in North America, Europe, Latin America, and offshore centres.

From an architecture standpoint, GLI-19 presupposes a system in which game outcomes are determined by a certified RNG, the game server holds authoritative state, and the client renders results without influencing outcome. The standard’s RNG requirements are detailed and have historically been one of the most scrutinised chapters during certification engagements. Statistical testing suites, seed management, and hardware versus software RNG distinctions all fall within this scope.

GLI-19 also addresses multi-game platforms, where a single system hosts diverse game types, and the certification must account for shared infrastructure. Operators building a platform that aggregates third-party game content must pay particular attention to how GLI-19 handles system boundaries: certification of the platform does not automatically certify the games sitting on top of it, and vice versa. In practice, operators should map their technical architecture before the certification scope is agreed, to avoid scope creep disputes mid-engagement.

GLI-33 Event Wagering Systems: Scope and Architecture

GLI-33 v1.1 was developed specifically for the event wagering sector, reflecting the structurally different risk and integrity profile of sports betting compared to RNG-based gaming. According to the standard’s introductory text, it is intended to be used by regulatory bodies, operators, and industry suppliers as a compliance guideline for technologies and procedures pertaining to event wagering. Crucially, the standard itself notes that it is not intended to represent a set of prescriptive requirements that every Event Wagering System and operator shall comply with, but rather establishes a standard regarding the technologies and procedures used to facilitate these operations.

“GLI-33 should be viewed as a living document that provides a level of guidance that will be tailored periodically to align with this developing industry over time as wagering implementations and operations evolve.” : GLI-33: Standards for Event Wagering Systems, v1.1, May 14, 2019, Page 2.

This framing is significant. Unlike GLI-19, which has reached a relatively mature version (v3.0) with well-established chapter structures, GLI-33 at v1.1 reflects a standard still in an evolutionary phase. The sports betting technology landscape, particularly the proliferation of in-play wagering, cash-out functionality, and API-driven odds feeds, has developed rapidly since the standard’s first publication. Compliance teams should treat GLI-33 certifications as potentially subject to revision and build change management provisions into their product roadmaps accordingly.

The technical chapters of GLI-33 are oriented around the distinctive components of an event wagering system: the wagering platform itself, odds management and feed integration, bet acceptance and validation logic, settlement processing and dispute resolution, system availability and fault tolerance, and audit trail integrity. The standard requires operators and suppliers to provide internal control documentation, credentials, and associated access to a production-equivalent test environment as part of the submission. This last requirement warrants early attention during pre-certification planning, as provisioning a compliant test environment for a live sportsbook can be operationally demanding.

Where the Standards Overlap

Despite their distinct primary scopes, GLI-19 and GLI-33 share a number of underlying technical requirements that compliance teams should recognise to avoid duplicating effort unnecessarily, or conversely, assuming that certification under one standard satisfies requirements normally covered by the other.  This is likely why most testing laboratories recommend certifying against both at the same  time to take advantage of the delta between the two and the significant overlap in coverage.

Both standards require robust system security controls, including access management, encryption of data in transit and at rest, and protection against unauthorised system modification. Both address audit logging and the integrity of transaction records, though the specific log formats, retention periods, and review triggers differ between the two. Both standards also address system availability, backup, and recovery procedures, reflecting the shared regulatory concern that player funds and bet records must survive system failure scenarios.

Responsible gambling system controls appear in both standards, though GLI-19 tends to provide more granular requirements in this area given its longer development history. Where a combined platform hosts both casino games and a sportsbook, the responsible gambling requirements from each applicable standard must be reconciled. Jurisdictions with their own responsible gambling technical mandates, such as the UKGC’s requirements under the relevant code provisions of the Licence Conditions and Codes of Practice, may impose additional layers on top of the GLI baseline.

Random number generation requirements arise in GLI-33 where event wagering systems incorporate virtual sports or simulated events. In those cases, GLI-33 draws on principles aligned with GLI-19’s RNG chapter, and certification teams at GLI will typically reference those requirements accordingly. Suppliers of virtual sports products embedded within a sportsbook should clarify with their GLI client services representative whether the RNG component will be evaluated under GLI-33 alone or whether GLI-19 RNG requirements will be applied in parallel.

Jurisdictional Adoption: How Regulators Apply These Standards

GLI describes its standards as globally accepted starting points that many jurisdictions use as a baseline in developing their regulations. This positioning is accurate but should not be read as implying uniform adoption. The reality is considerably more fragmented, and compliance professionals must conduct jurisdiction-by-jurisdiction analysis before assuming that a GLI-19 or GLI-33 certificate is sufficient for a given market.

In the Netherlands, the Kansspelautoriteit (KSA) publishes its own Keuringsschema (Assessment Scheme), currently at version 2.1 as published on 2 September 2024, which specifies the components of a gaming system that must be assessed and the requirements applicable to approved testing laboratories. The KSA designates specific approved testing bodies, including GLI Europe B.V. The scheme does not simply adopt GLI-19 or GLI-33 wholesale; rather, it specifies its own technical requirements and uses accredited labs, including GLI, to assess conformance. Operators targeting the Dutch market must work to the Keuringsschema, not directly to GLI standards alone.

In Denmark, Spillemyndigheden publishes its own Tekniske krav for onlinekasino og væddemål (Technical Requirements for Online Casino and Betting), currently at version 2.5 (effective 1 January 2025). This document operates as Spillemyndigheden’s primary technical standard and governs both online casino and sports betting in Denmark. Again, GLI standards inform but do not directly substitute for the Danish technical requirements. Operators seeking Danish authorisation must ensure their systems conform to the Danish technical requirements, with certification conducted through Spillemyndigheden’s own certification programme.

In North American markets, several state and provincial regulators have adopted GLI standards more directly. The extent of adoption, and which version is mandated, varies by jurisdiction and can change when a regulator updates its technical standards adoption schedule. Compliance professionals should verify current adoption status with the relevant regulator or qualified counsel in each target market rather than relying on historical adoption records.

The Combined Platform Problem

A growing proportion of licensees operate combined platforms that offer both RNG casino products and a sportsbook under a single player account. This architecture creates a certification complexity that neither GLI-19 nor GLI-33 alone fully resolves.

Where a jurisdiction requires GLI-19 certification for the casino component and GLI-33 certification for the event wagering component, the operator faces a dual-standard engagement. The shared infrastructure elements, including account management, wallet and transaction systems, authentication, and responsible gambling controls, must satisfy both sets of requirements. In some cases, the requirements are harmonious; in others, they impose different or more granular obligations. The test environment that GLI requires for GLI-33 must adequately replicate production wagering conditions, while a GLI-19 engagement will focus heavily on the RNG and game logic layer. Running these as sequential certifications carries timeline risk; running them in parallel requires careful coordination of test resources and technical documentation.

“Operators and suppliers are expected to provide internal control documentation, credentials and associated access to a production equivalent test environment with a request that it be evaluated in accordance with this technical standard.” : GLI-33: Standards for Event Wagering Systems, v1.1, May 14, 2019, Page 2.

In practice, operators should engage GLI’s client services team early to discuss scope mapping for combined platforms. GLI’s Composite Submission Requirements v2.0 document, available from the GLI standards portal, provides guidance on managing submissions that span multiple standards, and compliance teams should factor this into pre-certification project planning.

Change Management After Certification

Certification against either GLI-19 or GLI-33 is not a one-time event. Both standards contemplate ongoing compliance, and material changes to a certified system typically require notification to the relevant regulator and, depending on the nature of the change, retesting through the ITL. GLI publishes a Change Management Program Guide that outlines the procedures applicable to post-certification modifications. Compliance teams should integrate this document into their product release governance from day one.

For GLI-33 in particular, the standard’s own characterisation as a living document means that future revisions may impose new requirements on previously certified systems. Licensees operating in jurisdictions that mandate a specific version of GLI-33 should monitor GLI’s publication of revised versions and assess their jurisdictional obligations when updates are released. The question of whether a new standard version triggers mandatory recertification depends on the adopting jurisdiction’s rules, not on GLI’s publication alone.

Practical Decision Framework

Compliance teams approaching certification for the first time, or expanding into a new product category, should work through the following sequence before committing to a standard.

First, identify every jurisdiction in which the product will be offered and confirm whether that jurisdiction adopts GLI-19, GLI-33, a bespoke technical standard, or some combination. This analysis should be conducted with qualified legal counsel familiar with the target markets, as published adoption information is not always current or consolidated.

Second, characterise the product architecture precisely. A pure RNG casino product almost certainly requires GLI-19. A pure sportsbook with no virtual or simulated content requires GLI-33. A combined platform requires careful scoping of which standard applies to which system layer, and whether composite submission procedures apply.

Third, assess the timeline implications of dual certification if applicable. GLI-33 engagements for complex sportsbook platforms can be resource-intensive, particularly the requirement for a production-equivalent test environment. Building this into project timelines early, rather than discovering the requirement mid-engagement, is the single most effective way to avoid certification-related market entry delays.

Fourth, build change management into product governance from the outset. The GLI Change Management Program Guide and the change notification requirements of each target jurisdiction should be reflected in the product release process, not treated as a post-certification afterthought.

Industry consensus among ITL-experienced compliance professionals is that the most common source of certification delay is not technical deficiency in the product itself, but inadequate pre-engagement scoping, particularly for combined platform operators navigating dual-standard requirements.

Key Resources

GLI-33: Standards for Event Wagering Systems, v1.1 (May 14, 2019). Available for download from the GLI Standards portal at gaminglabs.com/gli-standards.

GLI-19: Standards for Interactive Gaming Systems, v3.0. Available for download from the GLI Standards portal at gaminglabs.com/gli-standards. Spanish and Portuguese translations available.

GLI Composite Submission Requirements, v2.0. Available from the GLI Standards portal. Governs submissions spanning multiple GLI standards.

GLI Product Certification Scheme (PC-QS-011). Governs the “Gaming Labs Certified” mark programme, including complaints and appeals procedures. Available from gaminglabs.com/gli-certified-mark.

GLI Change Management Program Guide. Available from the GLI Standards portal. Applicable to post-certification product modifications under all GLI standards.

Kansspelautoriteit Keuringsschema v2.1 (published 2 September 2024, mandatory from 1 October 2024). Available from the KSA website. Governs system assessment for online gambling licences in the Netherlands.

Spillemyndigheden Tekniske krav for onlinekasino og væddemål, v2.5 (effective 1 January 2025). Available from the Spillemyndigheden website. Governs technical requirements for online gambling authorisation in Denmark.