Certain aspects of a game are protected by copyright, while others are not. You certainly cannot copy the particular expression of the rules, but the mechanics themselves aren't copyrightable.

For example, why does the d20 Open Gaming License exist since Hasbro only releases game mechanics (at least usually) as open content, and this material is already not protectable by copyright law?

  • 3
    This question appears to be off-topic because it is about legal advice.
    – murgatroid99
    Sep 17, 2014 at 20:36

5 Answers 5


Fundamentally, the OGL exists to
(1) allow D&D 3.0 supplements to be made by 3rd parties and
(2) to ensure the 3.0 Dev Team could take their mechanics with them if they got fired.

(1) can be seen in the explosion of material in 2000-2002.
(2) can be seen clearly in Pathfinder and Arcana Unearthed.

While mechanics can't be copyrighted, and the US Patent Office almost never¹ grants patents on game mechanics, the Open Gaming License provides a means of reusing the literal text, and is a two-way license. Any mechanics you don't declare as product identity are likewise open.

This sharing could have been bidirectional with Wizards, but they appear to have decided not to go that route in the 3.x era.

The ability to use the literal text, combined with the lack of a formal OGL mark², only the D20 STL one, at the time of inception, allowed D&D-compatible d20 System games to flourish; they all "required" the D&D core rules³, and thus helped drive sales.

In general, it made D&D 3E one of the most used game systems in print... at least until Wizards moved on to 4E. And the D20 SRD is still one of the most used reference documents in the open gaming movement; D&D 4E no longer is part of that. (It will be interesting to see how 5E fares, and if it uses the OGL or not.)

Sidebar: Fonts

ML-111 specifies that typefaces are not copyrightable in the US unless individual characters constitute recognizable works of art.

ML-443 reads, in part:

Pursuant to Congress's judgement in the 1976 act and case law, the Copyright Office does not regiser claims to copyright in typeface designs as such, whether generated by a computer program, or represented in drawings, hard metal type, or any other form.

It does note that the program to generate a picture might be copyrighted, but the font itself can't be even if the font-as-program is.

The earlier ML-393 notes that font-as-program is unregisterable as the font itself is in fact not copyrightable, with the exception of fonts that are comprised of recognizable artwork.

It should be noted that the particular "look and feel" is a viable and defensible trademark, and for games, Fonts are part of that look and feel.

This isn't legal advice; for legal advice, contact an attorney at law licensed for your jurisdiction.


¹: The exceptions are few and thus highly notable. Wizards' patent on "Tapping" in card games being the most notable of the lot.
²: The OGL mark is a later add-on; Wizards only released the d20 system logo and a license for it requiring one to not include certain mechanics...
³: not that most of them can't be played without them. The missing content issue was solved in several d20 games by simply publishing an OGL-only web-enhancement with the missing rules.

  • So far, this is probably the best answer to my multiple questions. It clearly identifies that game mechanics aren't protected by copyright (and unlikely protected by patent), and explains that the OGL let's you copy the rules verbatim, where normally copyright would require you to express the rules in your own words. The only other nothing I can think of that isn't protected by copyright is the Font used in the game. Maybe I should edit the question to read "why does the OGL exist if game mechanics aren't protected by copyright"
    – user1873
    Jan 11, 2012 at 13:14
  • Excellent background on OGL in there. Thanks for providing that. Jan 11, 2012 at 18:12
  • 1
    Actually, fonts are copyrighted... it's just that they tend to be presumed licensed to the user. I've got several, in fact, that I can't use in commercial works without a separate (expensive) license.... And a specific combination of fonts constitutes a part of "look & feel"... which is trademarkable.
    – aramis
    Jan 12, 2012 at 1:27
  • Fonts aren't subject to copyright if you are talking about the graphic representation of a character/glyph, i.e. Uppercase 'A'. They are subject to copyright, if you are talking about a computer algorithm that can be used to generate instructions to display a character on a printer/computer screen, i.e. the computer software that actually generates an uppercase 'A'.
    – user1873
    Jan 16, 2012 at 4:27
  • The U.S Copyright Office actually has a Fact Sheet on games, telling you what and what is not covered.
    – jjb
    Jan 27, 2012 at 18:40

This is meant as a response to Chad, but the comment field wouldn't hold it all:

@Chad I am not a lawyer, but I have done a bit of reading on copyright and this does not seem right to me. It would be hard (not impossible) to patent a traditional board game, though some modern ones can involve some patented technology.

While it is strictly true that game mechanics (which are ideas) cannot be copyrighted, the term "expression" when dealing with copyrights is often interpreted quite broadly. If you are just re-wording a core idea from another game, you are probably falling afoul of copyright law.

And finally a license will not protect any invention, much less a game, from being claimed "as a unique creation by someone else." In patents, there is no "independent inventor" defense currently so as long as you were first, it doesn't matter if someone else also created it, and if they were first it doesn't matter if you developed it independently.

In copyright, the key dates to look at are when they were put in a fixed tangible medium.

Also, you are not required to aggressively defend either copyright or patents for them to maintain their validity. You are required to aggressively defende a trademark or the trademark will lose its validity, but that is different.

I think the release of some material under OGL was mostly a gift to the community, and if you must find a corprorate motive for it then think of "goodwill" or PR.

Again, I am not lawyer, if this is a question that you are going to make any decisions with real consequences on you may want to have an individual consultation with an actual lawyer (possibly one with experience in IP).


why does the d20 Open Gaming License exist since Hasbro only releases game mechanics (at least usually) as open content, and this material is already not protectable by copyright law?

Historical reasons. TSR, the original owners of Dungeons and Dragons, had a bad run at the internet early on. Their interpretation of how the copyright on D&D was applied was ridiculous and draconian. (For example, they claimed ownership of you product if you used the term "Hit Points," and had a single location from which D&D Materials could be distributed, including homebrewed rules -- you were expected to upload them to TSR for approval first.)

When Wizards of the Coast bought the remains of TSR, one of their desires was to get other people building supporting products for D&D, and talking about D&D on the internet. But with a bunch of restrictive rhetoric from TSR in the public mindscape, something had to be done to make it clear that this style of building-on was both acceptable and encouraged.

The Open Gaming License made it clear that building things "on top of" D&D was completely OK.


Traditionally, copyright protects the artistic expressions, which is to say those elements that are literary (text, dialogues, specific rule descriptions), graphical (any and all artwork) and auditory (music and sound effects) so long as those elements are original.

Essentially, everything but the mechanics (traditionally protected by patent in the case of novel mechanics) and trademark (brand identity in the form of game name, logo, and even characters if the expression is graphical as opposed to textual.)

However, there are two fairly recent trademark cases related to computer game cloning that have extended copyright into "patenty" territory:

Tetris Gets Permanent Injunction Against Xio | IP Watchdog

This is a great ruling because Tetris is arguably the most successful computer game of all-time, but the game's creator, Alexey Pajitnov, had to fight for decades to receive any compensation for his highly profitable creation.

SPRY FOX, LLC v. LOLAPPS, INC. Recent Ruling in Triple Town/Yeti Town Game App Dispute Provides Cautionary Lessons for Both EA and Zynga

My understanding is that these cases are considered something of a "third rail" that no one wants to go near, but due to recent uncertainty regarding patent eligibility of game mechanics (which, post-Alice, may be deemed too abstract, an unintended consequence of patent abuse which led to the Alice ruling,) copyright may need to be extended lest games constitute the only form of creative expression that is not protectable.[*]

[*] By this I mean to say that artistic content is utilized in non-abstract expressions of games, but strictly speaking, these do not constitute game IP in the sense that all games are algorithms (mathematical/logical). Thus, the game is the mechanics; the artistic content applied to games is merely "flavor".


The mechanics may not be protected by copyright but a process can be patented. It is possible that at some point if the creators rights are not protected then the creator could lose protection. The license helps to protect from that.

In addition the license protects the invention from being claimed as a unique creation by someone else. It limits (however broadly) the acceptable use of the product to those proscribed by the license. And it allows content creators to leverage an accepted standard game mechanic with content they they create, own, and profit from with out surrendering any of the rights of the original copyright to the written description of the mechanics.

Also just because something may be protected already under copyright, the license serves to enumerate, and reinforce those protections. Basically that means to say that these are the things that we care about the most. And it provides wording that is favorable to the creator that can be used in court should someone attempt to violate the license.

  • "surrendering any of the rights of the original copyright to the mechanics" you are mixing terms here. I think you mean patent. Maybe I should edit the question to include Trademark and Patent as well? Have any game mechanic patents been successfully litigated (I think I have heard that game mechanics might be patentable), or have they all been settled before a decision could be rendered?
    – user1873
    Jan 9, 2012 at 17:07
  • You can copyright the wording and the text. By open licensing you are saying its OK to redistribute and include it so long as you give credit and follow the license terms. I have edited the answer to hopefully clear up what i meant
    – Chad
    Jan 9, 2012 at 17:22

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