You cannot copyright game mechanics. Federal copyright law explicitly excludes systems, processes, and methods of operation from protection, and the rules of a game fall squarely into that territory. What copyright does protect is the creative expression built on top of those mechanics: the art, the animations, the music, the dialogue, the story, and the code. The rule that matching three gems clears them from a board belongs to everyone. The specific gems you drew, the sounds they make, and the code that runs the match do not.
Why the Law Excludes Mechanics
Section 102(b) of the Copyright Act says copyright protection does not extend to any “idea, procedure, process, system, method of operation, concept, principle, or discovery.”1Office of the Law Revision Counsel. 17 U.S. Code 102 – Subject Matter of Copyright: In General Game mechanics are systems and methods of operation. They are the rules that tell a player how the game works. The idea of a battle royale, where players drop onto a map and fight until one survives, is not something anyone can own. Neither is turn-taking, hit points, capture-the-flag, or arranging falling shapes into rows.
Two related doctrines push this exclusion even further, so the line sits farther from the mechanic than developers sometimes assume.
The merger doctrine says that when only a handful of ways exist to express a particular idea, the expression merges with the idea and loses protection. If a puzzle game’s rule is “arrange falling shapes to complete rows,” the visual choices for showing that rule are limited, and a court will ask whether the developer’s choices were genuinely creative or simply the inevitable result of the rules. The fewer creative options, the thinner the copyright.
The scènes à faire doctrine strips protection from elements that are standard features of a genre. A health bar in an action game, an inventory screen and quest log in a fantasy RPG, a minimap in a real-time strategy game, a capture-the-flag mode in a shooter — these belong to the genre, not to whoever used them first. If one developer could lock them up, nobody else could build a recognizable game in the same genre.
Where “Not Copyrightable” Stops
“Mechanics aren’t copyrightable” does not mean you can build a pixel-for-pixel copy of someone else’s game and call it new. The 2012 case Tetris Holding v. Xio Interactive is the clearest illustration. Xio released a game called Mino that replicated Tetris’s rules along with its specific visual presentation: the dimensions of the playing field, the bright colors of the pieces, and the way completed lines disappeared. The court agreed that the abstract rules of Tetris were unprotectable ideas. It also found that Xio had gone far beyond copying rules. The look and feel of the game, the particular artistic choices layered on those rules, crossed into protectable expression, and Xio lost.
The practical read: another developer is free to make a falling-block puzzle game. They are not free to copy your art, your color choices, your sound design, or your specific presentation.
What Copyright Actually Covers in Your Game
A game is packed with creative work that qualifies for copyright, and registering it is what turns that copyright into something enforceable.
Audiovisual Elements
The Copyright Act defines “audiovisual works” as a series of related images intended to be shown by machine, together with any accompanying sounds.2Office of the Law Revision Counsel. 17 U.S. Code 101 – Definitions Games fit the definition, and the U.S. Copyright Office instructs applicants to register them under the “Motion Picture/AV Work” category.3U.S. Copyright Office. Help: Type of Work This registration covers the graphics, character designs, animations, interface art, and overall visual presentation as experienced during gameplay.
Code, Story, and Text
A game’s plot, dialogue, and on-screen text are literary works. So is the code. The Copyright Act defines “literary works” as works expressed in words, numbers, or other verbal or numerical symbols, regardless of the medium.2Office of the Law Revision Counsel. 17 U.S. Code 101 – Definitions Both source code and compiled object code fall under this, which is why unauthorized copying of code can support an infringement claim even when the visual output looks different.
Music and Sound
Original scores, licensed tracks, and custom sound effects are separately copyrightable as musical works and sound recordings. A single game can contain dozens or hundreds of individually protected audio assets.
Register Before You Ship, or Within Three Months
Copyright exists the moment a work is fixed in tangible form. You don’t have to register to have a copyright. But registration is what unlocks the enforcement tools that make copyright worth having, and the timing controls what remedies are on the table.
Register before infringement begins, or within three months of first publication, and you can seek statutory damages of $750 to $30,000 per work infringed. Willful infringement pushes the ceiling to $150,000 per work, and you become eligible to recover attorney’s fees.4Office of the Law Revision Counsel. 17 U.S. Code 504 – Remedies for Infringement: Damages and Profits Miss that three-month window and register after infringement has already started, and you are limited to proving actual damages, which usually means hiring economists to reconstruct lost profits.5Office of the Law Revision Counsel. 17 U.S. Code 412 – Registration as Prerequisite to Certain Remedies for Infringement Indie developers get burned on this constantly. They ship, skip registration, discover a clone months later, and find their strongest tools are gone.
How to Protect the Mechanics Themselves
Copyright is not the only tool. Other legal frameworks can reach parts of a game that copyright cannot.
Patents
A utility patent can protect a “new and useful process, machine, manufacture, or composition of matter.”6Office of the Law Revision Counsel. 35 U.S. Code 101 – Inventions Patentable Unlike copyright, this can cover a novel game mechanic. Namco patented playable mini-games during loading screens, blocking every other developer from using that feature for twenty years. Warner Bros. patented the “Nemesis System” from Middle-earth: Shadow of Mordor, which tracks how enemies remember and adapt to a player’s actions. These are exceptions. A patent requires proving the mechanic is truly novel and non-obvious, the application takes years, and costs typically run into five figures. Most mechanics don’t clear that bar.
Trademarks
Trademark law protects words, names, symbols, or devices that identify the source of goods and distinguish them from competitors.7Office of the Law Revision Counsel. 15 U.S. Code 1127 – Construction and Definitions For a game, that means the title, logo, character names used as brand identifiers, and marketing slogans. Trademark stops a competitor from releasing a game with a confusingly similar name or logo. It has nothing to say about the game’s rules or systems.
Trade Secrets
Proprietary algorithms, matchmaking formulas, unreleased source code, and internal development tools can qualify as trade secrets if the owner takes reasonable steps to keep them confidential and the information derives economic value from being secret.8Office of the Law Revision Counsel. 18 U.S. Code 1839 – Definitions Protection lasts as long as the secret stays secret, which means NDAs, limited internal access, and marking documents as confidential. Once the information becomes publicly known through reverse engineering, a leak, or deliberate disclosure, the protection evaporates.
End User License Agreements
A EULA is a contract between the developer and the player, and it can prohibit conduct that IP law does not reach on its own. Common EULA restrictions include bans on reverse engineering, creating derivative works, and extracting game assets. A violation is a breach of contract rather than infringement. Enforceability turns on whether the player had a meaningful opportunity to review the terms and affirmatively agreed to them, typically by clicking “I accept” before accessing the game. Courts have generally upheld these clickwrap agreements when the terms are presented clearly and the user must take an affirmative step to proceed.