Game Asset Licensing and Open Source in Games

Start with the rights in the build

Copyright can protect artwork, models, textures, animation, music, recordings, dialogue and code. One audio track may involve separate rights in the composition, lyrics, master recording and performers. A licence covering one layer may not clear the others. Copyright generally protects expression rather than an abstract game idea, but trademarks, designs, privacy, publicity rights and contracts may also apply.

A worldwide digital release crosses legal systems. The US, EU Member States and UK differ on ownership defaults, exceptions and moral rights. A licence’s governing-law clause helps interpret the contract; it does not necessarily answer every copyright question in every market. Define territory, platforms, duration, sequel and DLC rights, marketing, updates, sublicensing and permitted player access expressly.

1. Check each asset against its actual use

For every asset, ask whether the studio may modify it, combine it with other work, include it in a commercial game, distribute it through each planned platform, use it in trailers and store pages, include it in DLC, and let players access or extract it. Record the licence version, purchase evidence, source and any asset-specific terms. “Royalty-free” describes a fee model; it does not mean public domain or unrestricted use.

Marketplace terms are not universal. For example, Unity’s Asset Store EULA lets a studio embed a non-restricted asset in a game only together with substantial original content, so that the asset is not a substantial part of the product. It does not let players sell, transfer or lend the asset, bars monetising an asset in a product whose main purpose is user-generated content without authorisation, and bans using assets to train AI models. A contractor needs their own licence. Restricted assets follow their own terms, and SDKs and editor extensions carry extra limits. The EULA also says open-source licences control their components where terms conflict. Read the listing, EULA and asset-specific terms together. Unity Asset Store EULA.

2. AI-generated assets need two reviews

Check the AI tool contract for commercial use, output restrictions, confidentiality, retention, training on uploads and any indemnity. Separately inspect outputs for recognisable copyrighted material, brands, likenesses or voices. “Generated by AI” does not clear third-party rights.

Ownership is a separate question. The US Copyright Office’s 2025 report says human-authored expression and creative selection or modification may be protected, but purely AI-generated material and prompts alone generally are not. UK law contains a rule for certain computer-generated works, while its application to modern generative systems is fact-sensitive and the rule may change. EU copyright centres on original human intellectual creation. Keep records of the tool, terms, references, prompts, human edits and selection. Treat exclusive ownership claims cautiously where human authorship is limited. US Copyright Office, AI Part 2; UK CDPA, section 9.

3. Secure ownership and chain of title

Keep a record showing how rights pass from each creator to the studio, publisher, platforms and players. Contracts should identify deliverables; assign new rights or grant a sufficiently broad licence; cover edits, derivatives, ports, localisation, DLC, marketing, updates, sublicensing and continued use after termination; and address background tools, third-party materials and subcontractors. Obtain performer releases for voice and motion capture. Moral rights may need consent or waiver where local law permits.

Practical rule: sign contributor and outsource agreements before work begins. Name permitted pre-existing tools and give the studio the licence needed to exploit them as embedded. Require advance disclosure and approval of third-party assets, open-source code and AI use.

4. Open source: read the exact licence

Open source permits use subject to conditions. Keep exact licence texts, notices, component versions and modifications. Review transitive dependencies and the licence actually shipped, not just a repository badge.

Classify every engine component, plugin, SDK and library: editor-only tool, runtime module, static or shared library, server component, build tool or separate service. Ask what is modified, linked, compiled into the game or delivered to players, and whether the licence has a network clause. There is no universal static-versus-dynamic rule. If the answer is uncertain, replace the dependency, get a commercial licence or obtain advice before production locks it in.

5. Notices, source and player content

Generate a release-specific third-party notices file from the shipped build. List each component, version, licence, modifications, copyright line, attribution and NOTICE text. Put notices where the licence permits: in-game credits, documentation, an installer or a “Third-Party Licences” file. For copyleft components, prepare the required corresponding source and a working delivery method before release; retain build scripts and offer records for the period the licence requires.

Mod support creates two permissions: the studio grants players limited rights to use game tools and content, while modders grant the studio and platform rights to host, display, distribute, adapt for compatibility and remove submissions. Terms should address monetisation, moderation, takedowns and third-party material. Ban uploads of unlicensed music, ripped models, trademarks and personal data. A modder warranty does not remove the studio’s own risk.

Review platform and middleware agreements separately from copyright licences. Steam Workshop supports different distribution models, including paid items; its Workshop documentation and Steam agreements govern the service relationship. Engine and SDK terms may separately restrict seats, data use, branding, anti-cheat or redistribution. Recheck the terms accepted for the specific product before each release. Steam Workshop documentation.

Release checklist

1. Build an asset and dependency register

   Owner, source, version, licence, project, territory, expiry, approvals and evidence.

   Start here

2. Secure signed contributor rights

   Employees, contractors, studios, composers, performers and subcontractors; list background tools and third-party content.

3. Map licences to actual distribution

   Game build, DLC, trailer, store page, server, mod kit, user content and each platform.

4. Scan and review the dependency tree

   Check exact versions, transitive packages, modifications, linking and network use.

5. Generate notices and source materials

   Validate attribution, licence copies, NOTICE and source delivery against each applicable licence.

6. Clear player-facing permissions

   Review EULA, mods, workshop and takedown processes; confirm players cannot reuse licensed assets beyond the grant.

7. Hold release on unresolved rights

   Replace, remove or clear the item, and archive the exact build and evidence shipped.

Frequently asked questions

See also: AI-Generated Content and Copyright; Hiring a Software Contractor: Who Owns the Code; Licence agreements for a blockchain game in several countries. Services: legal support for GameDev and GameFi.