oreilly.comSafari Books Online.Conferences.


Open Source and Free Documentation Licenses, Part 3: The Open Gaming License

by Andrew M. St. Laurent, author of Understanding Open Source and Free Software Licensing

As described in parts one and two of this series, open source licensing principles are generally, if not exclusively, associated with software. These principles may be less readily applicable to non-software works, such as documents.

Nonetheless, there are a number of licenses and projects directed at applying open source and free software licenses to such works. In my book, Understanding Open Source and Free Software Licenses, I discuss the Creative Commons, an ambitious project intended to apply the power of open source development to a wide variety of works, including music, video, and the fine arts, as well as documents. In part one of this series, I discussed the GNU Free Documentation License (FDL), a license that follows the GNU licensing philosophy by permitting free modification and distribution of a given document, upon the condition that the document so distributed or modified also be licensed under the GNU FDL, and in part two, I discussed the Open Publication License, which operates in a manner similar to the BSD, MIT, and other "academic" licenses.

This, the third and final article of the series, describes the Open Gaming License (OGL), a license designed to open source license certain parts of the Dungeons & Dragons roleplaying game, and two related documents, the d20 System Trademark License and the d20 System Trademark Guide Version 5.0.

Like some of the open source and free software licenses discussed in my book, the OGL was designed for one "application." Wizards of the Coast (WoTC), the successor to TSR, Inc., the developer of the Dungeons & Dragons gaming system, applied the OGL to what the company has termed the System Reference Document. The System Reference Document (SRD) is essentially an abstract of the gaming mechanics of WoTC's Dungeons & Dragons game, version 3.5. The SRD provides almost all the elements needed to play a role-playing game that WoTC calls the "d20 System." The d20 System is essentially identical to Dungeons & Dragons, except that it lacks rules describing the creation and advancement of characters within the game world and does not include any features that reflect unique campaigns, such as unique characters, deities, or artifacts.

Related Reading

Understanding Open Source and Free Software Licensing
By Andrew M. St. Laurent

As explained in the d20 System Concept FAQ, WoTC developed the OGL and the d20 System concept in an effort to limit the proliferation of tabletop roleplaying games that were premised on incompatible gaming systems. WoTC believes, sensibly enough, that while functional and readily comprehensible game mechanics are vital to tabletop roleplaying games, those mechanics are not the reason why gamers play games. The real attraction of such games is the sense of mystery and adventure imbued by individual authors in their characters, settings, and campaigns. The OGL and the d20 System are intended to create a standard set of mechanics that would allow gamers to enjoy the works of many different authors without undertaking the labor of learning an entirely new gaming system. This idea is not a new one: Steve Jackson Games, for example, introduced the Generic Universal Role Playing System (GURPS) in the 1980s, and it continues going strong. While there are other "universal" gaming systems and, indeed, other open source roleplaying games, the d20 System concept is nonetheless significant, because of the power of the brand being licensed: Dungeons & Dragons was the first, and remains the most important, roleplaying game ever written.

The OGL and the d20 System have achieved at least a qualified success. While there are still many, many competing game systems, a number of publishers have taken the opportunity to develop works under the d20 System trademark: there are currently hundreds of such works in print.

The OGL is, by itself, a relatively simple agreement. Additional restrictions are, as described below, contained in the d20 System Trademark License (RTF file) and the d20 System Trademark Guide (RTF file).

In overview, the OGL permits wide-ranging use of the intellectual property contained in the SRD in the creation and distribution of works relying on the SRD game mechanics or works that are themselves revisions or modifications of the SRD. The d20 System Trademark and the related d20 System Trademark Guide, by contrast, impose substantial restrictions on the content and character of works that can be branded with the d20 System logo. Such works can extend, but cannot modify, the fundamental game mechanics in the SRD. In addition, works that are branded with the d20 System logo cannot describe character creation or advancement. In order for gamers to create characters (at least according to a process described in a published work), those gamers must rely on WoTC's own products, in particular, WoTC's Player's Handbook.

The OGL begins with Section 1, "Definitions." The preamble to the license notes that the license itself is copyrighted by WoTC. This definitional section is the most important section of the license, and its definitions of key terms really control every aspect of the license.

The first definition is the "Contributors," that is to say, those persons licensing their intellectual property under the OGL. In the case of the d20 System, this is, in the first instance, WoTC as successor-in-interest to TSR and the creators and many contributors to the Dungeons & Dragons system. "Derivative Material" is the next definition, and provides a definition that is for our purposes substantially identical to the term "derivative work" as that term is used in copyright law. It means essentially any work that is substantially derived from or a modified version of a given original work. "Distribute" means to distribute a work in any form, including sales, leases, and broadcasts.

Section 1 also defines the two terms critical to the functioning of the d20 System and the d20 System Trademark License: "Open Game Content" and its opposite "Product Identity." "Open Game Content" is that part of a work that consists of game mechanics and only game mechanics. "Product Identity" is everything else: characters, plots, campaigns, adventures, names, descriptions, unique items and encounters, dialogue--everything that makes a given gaming experience unique and enjoyable. In the context of the d20 System, WoTC has designated everything within the SRD as "Open Game Content." Everything else in the Dungeons & Dragons universe is "Product Identity" that the OGL does not license. How these terms apply to work created by persons other than WoTC is described in more detail below.

Section 1 also defines "Trademark" in a way that is substantially identical to that used in American intellectual property law. A trademark is a mark, generally either a name or logo, that uniquely identifies a particular work as being that of a particular manufacturer. Section 1 defines "Use" as the formatting, editing, or modification of a work so as to create "Derivative Material" as just defined. "Distribution" is also, critically, a form of use. Finally, Section 1 defines "You" as the licensee. This type of definitions section is typical of open source licenses.

Section 2 is the operative section of the license and is reprinted in its entirety here:

"2. The License: This License applies to any Open Game Content that contains a notice indicating that the Open Game Content may only be Used under and in terms of this License. You must affix such a notice to any Open Game Content that you Use. No terms may be added to or subtracted from this License except as described by the License itself. No other terms or conditions may be applied to any Open Game Content distributed using this License."

This section states three things. First, in order for Open Game Content to be such, it must contain a notice stating that the Open Game Content is available for use under the terms of the OGL. Second, any Open Game Content "Used" by a licensee, which would include any redistribution of the original Open Game Content created by the WoTC, must contain such a notice and accordingly be subject to the terms of the OGL. This has very significant consequences for those who would create derivative works based on OGL-licensed material. Because such a notice must be attached to, and the OGL must accordingly apply to, any Open Game Content that is Used, and because "Use" includes the creation of derivative works from the Open Game Content, any modification, extension, or translation of Open Game Content must itself be licensed under the OGL. This is the clear import of Section 2 and seems to the be the intent of the OGL's drafters, at least one of whom identifies the GNU General Public License (GPL) as his or her inspiration.

Accordingly, if someone extends the Open Game Content in the SRD (by, for example, changing the rules applicable to combat), such an extension must, under the terms of the OGL, itself be licensed under the OGL. That author could not subsequently distribute that material under a license other than the OGL, including, for example, a proprietary license.

Thirdly, no changes may be made to the OGL, except as provided by the OGL itself (specifically, Section 9, described in more detail below), and no additional terms or conditions may be applied to Open Game Content distributed under the OGL. These requirements are intended to prevent any limitations that would function on top of those imposed by the OGL, such as the requirement that a licensee pay royalties to the licensor. This is similar to a provision in Section 6 of the GPL.

Section 3 of the OGL simply states that Use of the OGL-licensed works constitutes an agreement to be bound by the terms of the OGL. Section 4 is the grant of rights by the OGL: by agreeing to the terms of the OGL, the licensee can use (or Use) the OGL-licensed work without paying royalties under the terms and conditions specified by the OGL.

Section 5 imposes an affirmative representation on licensees who contribute work that such work is their original work or that they otherwise have rights to license the work under the OGL. A distribution of such work that is not in fact the creation of or otherwise license-able by the author would violate the OGL, resulting in the termination of the contributor's own rights under the OGL, as described in Section 13, detailed below.

Section 6 requires that any distribution of OGL-licensed material contain appropriate copyright notices. Accordingly, if a licensee distributes a copy of the SRD, the copyright notice must include WoTC's copyright in the SRD. If the licensee includes his or her own extensions or modifications, he must include his or her own copyright notice applicable to those extensions or modifications.

Section 7 addresses "Product Identity." As previously discussed, this section bars any "Use" of "Product Identity." However, it goes beyond that to bar any statement by a licensee that a work is compatible with any other work containing Open Game Content, except pursuant to a specific, separate agreement. This is described further in connection with the d20 System Trademark License below.

Section 8 requires that a licensee who distributes a work containing both Open Game Content and (the licensee's own) Product Identity (as virtually every work will), must indicate that portion of the work that is Open Game Content, by use of gray shaded boxes or the like.

Section 9 grants WoTC the right to update the OGL as it sees fit. This allows any licensee to rely on any version of the OGL in determining their rights. This may cause some concern on the part of licensors under the OGL other than WoTC, but given the very broad grant of rights represented by the OGL itself, it seems unlikely that WoTC could or would make any change to the OGL that would undermine any interest of such licensors.

Section 10 simply states that a copy of the license must accompany every OGL-licensed work. Section 11 provides that the name of a Contributor (obviously including WoTC) cannot be used to market OGL-licensed work without permission of that Contributor.

Section 12 states that in the event any provision of the OGL cannot be followed for a given work, because of a statute or court decision, that work cannot be distributed pursuant to the OGL and effectively cannot be distributed at all. This is parallel to Section 7 of the GPL, and serves to prevent any distribution that would undermine the open source ideal of the OGL. For example, a court could order, as a remedy for infringement, that an OGL-licensed work only be distributed upon payment of one dollar to the party whose work was infringed upon. Even if the distributor was willing to collect that payment and purchasers willing to pay it, no such distribution would be permitted under the OGL. Because payment of any royalties would violate Section 4, Section 12 bars any such distribution. In that case, no distribution of the work could be made at all. A distribution without royalties would violate the court order; a distribution with royalties would violate Section 4. The solution of Section 12 is to bar any distribution at all under such circumstances.

Section 13 addresses termination. In the even that a licensee fails to comply with any of the terms of the license, his or her rights terminate automatically, without notice, 30 days after he becomes aware of the breach. Section 13, again like the GPL, provides that sublicenses validly granted survive such termination. For example, if WoTC licenses a work under the OGL to A, and then A sublicenses that work properly to B, C, and D, then even if A breaches the OGL and his or her rights are terminated, the rights of B, C, and D continue, so long as they are in compliance with the OGL.

Section 14 address "Reformation," a legal process whereby a court revises a contract to effect what the court considers to be its intended purpose. The section permits such reformation only to the extent necessary to render a section enforceable. This section is typical of commercial contracts. Moreover, because it is a change contemplated by the agreement, it is not in tension with Section 2's limitations on modifications of the OGL.

Section 15 is simply the copyright notice identified in Section 6, which must be included in every distribution.

The OGL concisely and clearly describes what is and is not "Open Game Content" and the limits on the modification and distribution of such works. The licensee is granted an extensive variety of rights. The licensee may modify the Open Game Content to suit his or her own purposes and distribute it, albeit only under the OGL. The licensee may freely incorporate Open Game Content, either modified or not, into his or her own works along with his or her own Product Identity and feel confident that such Product Identity will be protected by copyright.

Nonetheless, an author may be concerned about the limitations in OGL's Section 7 on the use of trademarks. These limitations bar even the indication that a licensed work is compatible with the d20 System or the Dungeons & Dragons system. This creates obvious and real impediments to distributing work in the marketplace. How, after all, can a consumer know that a particular work (such as an adventure or campaign) is designed to be compatible with the d20 System and Dungeons & Dragons if the creator can't even say that on the product itself?

This issue is dealt by the d20 System Trademark License and the related d20 System Trademark Guide, which are separate and distinct agreements, granting separate and distinct rights from the OGL. These are rather extensive documents that could be explained in detail in an article of their own. They are accordingly addressed only briefly here.

The d20 System Trademark License, in sum and substance, permits licensees to place the "d20 System" logo and name on their works (all of which are, presumably, derivative works of the OGL-licensed SRD) and to make use of other WoTC licensed trademarks to indicate compatibility. In exchange, the licensee must agree to abide by certain quality standards and by certain other restrictions. In the event the licensee fails to comply with these requirements, the licensee is required, under most circumstances, to cure the breach within 30 days of receiving notice from WoTC. In the event the licensee fails to cure the breach, the licensee loses all of the rights granted by the agreement.

The quality standards and the other restrictions are described in the d20 System Trademark Guide (the "Guide"). The quality standards prohibit any licensed work to include excessively graphic sexuality or violence or any text or graphic that is intended to inflame prejudice against real-world minorities. All of these standards are applied at the discretion of WoTC.

The Guide, as previously noted, also prohibits any description of character creation or advancement of character levels. This is to done to retain the WoTC's monopoly on d20 System works that describe these functions. The Guide contains certain "Defined Game Terms," all of which relate to fundamental mechanics of the game. As a condition of using the d20 logo (and other rights), the licensee gives up the ability to modify or extend the definition of any of the "Defined Game Terms." The obvious purpose of this requirement is to maintain compatibility across all d20-licensed products. The Guide not only permits but requires that the d20 System logo be displayed on all licensed products. While certain references to WoTC works are permitted (for example, to sections of the Player's Handbook or the Dungeon Master's Guide), other references are in fact required. On either the front or the back cover, the licensee must clearly indicate that the work requires the use of WoTC works, namely the Dungeons & Dragons Third Edition Core Books or the d20 Modern Roleplaying Game.

Finally, the Guide also prohibits any "Interactive Game" from being licensed to use the d20 System logo. This essentially bars the creation of any computer games or software under the trademark license. This is because WoTC has entered into exclusive agreements with electronic game creators for such rights.

None of the Guide's requirements, of course, apply to those persons who choose only to be licensed under the OGL. Any person is free to extend and modify the SRD, make it the basis for his or her own campaign, and to sell that work in the marketplace, without regard to the Guide's quality standards or limits on the modification of the "Defined Game Terms." Such a licensee, however, cannot market his or her product as a d20 System product.

The OGL represents, at the very least, an interesting experiment in the application of open source principles to a field of endeavor other than software. It has so far had not insignificant success, as a number of licensees (under both the OGL and the Trademark License) have chosen to distribute d20-System-branded products. Its effectiveness in reinvigorating the tabletop roleplaying game market, however, remains to be seen.

Andrew M. St. Laurent is an experienced lawyer with a long-time interest in intellectual property, particularly software licensing.

Return to

Sponsored by: