Steal This Mechanic: Why Game Rules Are Free for All

There’s a beautiful secret in the world of game design. It’s the kind of thing that makes lawyers frown and designers smile like they just drew a full hand of wild cards. Ready? 

Game mechanics can’t be copyrighted.

Yep. That movement rule from a skirmish game? The way someone combined deck-building with dice rolling? All fair game. 

It’s the result of a long-standing legal precedent, courtesy of the Supreme Court, that basically said, “You can’t copyright how something works—just how you describe it.”

Back in 1879, a case called Baker v. Selden made it clear: writing a book about a system doesn’t give you ownership of the system itself. Baker v. Selden is a landmark Supreme Court case that clarified the boundary between copyright and patent law through the idea-expression dichotomy. 

Charles Selden authored a book describing a new system of bookkeeping and held a copyright on it, but when W.C.M. Baker published a similar system and found commercial success, Selden’s widow sued for copyright infringement. Lower courts sided with Selden, but the Supreme Court reversed, ruling that while Selden’s written explanation and illustrations were protected by copyright, the method of bookkeeping itself was not—it could only be protected by patent. The Court concluded that copyright does not grant exclusive rights to “useful arts” or functional systems, only to their expression. This case has major implications for game design today: game mechanics, like bookkeeping systems, are considered functional methods and cannot be copyrighted—only the unique expression of those mechanics (such as the text, artwork, or design of a rulebook) is protected.

The Baker v. Selden ruling laid the judicial groundwork for the Copyright Act of 1976. Specifically, Section 102(b) of the Act states that “In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery…” — echoing the logic from Baker v. Selden.

What does this mean for us, the game designers? It means the mechanics—the gears and levers that make our games go—are part of a shared toolbox. Worker placement, deck-building, and cooperative play leap across genres and themes, keeping their function but serving new stories. 

Thanks to Baker v. Selden and the Copyright Act of 1976, designers are free to reuse and remix these mechanical blueprints, crafting new experiences by changing the context, flavor, and flow. 

And thank goodness for that because while expression is copyrightable (think: your game’s art, story, character names, and exact rulebook text), function is not. That means when you fall in love with a game’s tension or tempo, you don’t have to reinvent the wheel—you can remix it, iterate on it, and make it sing in a new key.

This doesn’t mean you should copy someone’s game wholesale and slap a new name on it. We still value creativity, innovation, and giving credit where it’s due. But you can borrow the mechanic, evolve it, and build something fresh.

In a world that often locks down creativity behind walls of legalese and licensing, game design remains one of the most collaborative and generous playgrounds out there. We share ideas not because we have to, but because that’s how we all level up.

So next time you play a game and think, “Wow, I love how this works,” know this:

• You don’t have to ask permission.
• You don’t need a lawyer.
• You just need a good idea—and the will to make it your own.

Steal the mechanic. Make it better. Then pass it on.

A quick note: Of course, there are always exceptions. A reader asked about a Warner Bros. case from 2016. They patented the Nemesis system from Shadow of Mordor, protecting its unique blend of dynamic NPCs, social hierarchies, and revenge mechanics, protecting the system until 2036. They used patent law to lock down specific systems. 

• Copyright protects expression (e.g., the written rules of a game, character designs, narrative text), not the ideas or mechanics themselves
• Patents, on the other hand, can protect methods, systems, and processes—but only if they’re novel, non-obvious, and useful

Warner Bros. didn’t try to copyright the Nemesis system. That would’ve been tossed out. Instead, they applied for and received a utility patent—which is more like saying, “We invented a specific kind of engine for games, and here’s exactly how it works.” If the patent office agrees it’s sufficiently innovative, it gets locked down—for up to 20 years.

It’s a rare move in game design, but it shows that when a mechanic is complex, novel, and clearly defined, it can be protected—for a while.