United States: Appeals Court: World of Warcraft "Bots" Do Not Infringe Video Game Developer's Copyright But DMCA Claim Survives

Last Updated: December 23 2010
Article by Nicole I. Hyland

This article first appeared on Entertainment Law Matters

Blizzard, creator of the popular online game World of Warcraft (WoW), recently suffered a setback in its litigation against MDY Industries, which sells Glider – a software "bot" that automatically plays some of the early levels of the game. The Ninth Circuit reversed a $6.5 million judgment for Blizzard, finding no liability for secondary copyright infringement. A party may be liable for secondary infringement if it either (1) intentionally induced another person's direct infringement (known as "contributory infringement") or (2) had the right and ability to control another's infringing activities and derived a financial benefit from those activities (known as "vicarious infringement"). In either case, direct infringement must be established before secondary liability can attach.

To establish secondary infringement against MDY, Blizzard had to show that Glider users infringed Blizzard's copyright by violating a Terms of Use (ToU) provision that prohibits the use of "cheats, bots, 'mods,' and/or hacks." The appeals court held that WoW players who used Glider in violation of the ToU did not infringe Blizzard's copyright. Thus, MDY could not be secondarily liable for infringement.

The decision was a mixed bag of good news and bad news for the parties – as well as their customers. Although the court exonerated MDY for copyright infringement, it found the "bot" maker liable for violations of the Digital Millennium Copyright Act (DMCA). In addition, the court ordered a trial on Blizzard's claim that MDY tortiously interfered with Blizzard's user agreements. While WoW players may be happy with the ruling that license and ToU violations do not necessarily constitute copyright infringement, they might be surprised to learn they do not actually own their copies of the WoW software program, according to the court's decision.

WoW Users Do Not "Own" Their Software:

Before determining whether Glider users committed copyright infringement, the court had to ascertain whether they were "owners" or "licensees" of the WoW software. To answer this question, the court turned to its decision in Vernor v. Autodesk, Inc., an important software licensing case that we covered in a previous post. As discussed in Vernor, in order to run any software program, a user's computer must create a copy of the program in the computer's random access memory ("RAM"), which may infringe the seller's copyright.

Under Vernor, users who "own" a copy of the software program may invoke the "essential step" defense to copyright infringement, because copying the program into the computer's RAM is essential to running the program. However, users who license a software program are not protected by the "essential step" defense and, therefore, their use of the program must comply with the seller's license agreement and terms of use. Applying Vernor's analytical framework, the court concluded that purchasers of WoW are licensees, rather than owners of the software. Thus, when their computers copy WoW software into RAM, users may infringe Blizzard's copyright, unless their use complies with Blizzard's license and ToU.

Glider Users Are Not Infringers:

Having determined that WoW players are licensees and not owners, the central issue facing the court was whether Glider users who violated Blizzard's prohibition against "bots" committed copyright infringement or merely breached their license agreements. The answer turned on a somewhat arcane distinction between a license "condition" (which limits the scope of a license) and a "covenant" (which is merely a contractual promise). According to the court, if the prohibition against bots was a "condition," Glider users committed copyright infringement, making MDY liable for secondary infringement. If, on the other hand, the prohibition was a "covenant," Glider users merely breached their license agreements.

Examples of license "conditions" might include restrictions against distributing copies of the software program or creating derivative works. By contrast, a prohibition against harassing other gamers online constitutes a "covenant" because it does not implicate Blizzard's "exclusive rights of copyright." The court held that Blizzard's prohibition against using "bots" was a covenant, not a condition, because it did not implicate Blizzard's "exclusive rights of copyright." Thus, Glider users who violated this prohibition did not commit copyright infringement and, by extension, MDY could not be held liable for secondary copyright infringement.

MDY Violated the Digital Millennium Copyright Act (DMCA):

To combat Glider and similar unauthorized programs, Blizzard developed a technology called Warden, which is able to detect and ban players who use such programs. In response, MDY modified Glider to include anti-detection features and sold a subscription service, Glider Elite, which offered additional protections against Warden.

The appeals court held that MDY's anti-detection technology violated Section 1201(a)(2) of the DMCA, which prohibits trafficking in products that circumvent technologies designed to control access to copyright protected works. In reaching this conclusion, the court rejected the Federal Circuit's seminal ruling in Chamberlain Group, Inc. v. Skylink Techs., Inc. holding that circumvention technologies which do not facilitate copyright infringement do not trigger liability under Section 1201(a)(2) of the DMCA. Thus, even though – as discussed above – the court ruled that Glider did not facilitate copyright infringement, MDY could still be liable under the DMCA for circumventing Warden's detection features.

What the Decision Means:

This decision could have significant implications for another lawsuit filed by Blizzard against three alleged hackers who created "cheats" for StarCraft II, another popular Blizzard game. Blizzard has alleged similar claims of secondary copyright infringement against the defendants in that case. This decision may lead to dismissal of those copyright claims, although the defendants may still be liable for tortious interference with Blizzard's contracts.

The decision also creates a conflict between the Federal Circuit and the Ninth Circuit on an important question of federal statutory interpretation – whether a plaintiff seeking to hold a defendant liable under the DMCA for selling a technology-circumventing device must prove that the device facilitates copyright infringement. This conflict may call, ultimately, for Supreme Court resolution.


This alert provides general coverage of its subject area. We provide it with the understanding that Frankfurt Kurnit Klein & Selz is not engaged herein in rendering legal advice, and shall not be liable for any damages resulting from any error, inaccuracy, or omission. Our attorneys practice law only in jurisdictions in which they are properly authorized to do so. We do not seek to represent clients in other jurisdictions.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

Nicole I. Hyland
In association with
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Check to state you have read and
agree to our Terms and Conditions

Terms & Conditions and Privacy Statement

Mondaq.com (the Website) is owned and managed by Mondaq Ltd and as a user you are granted a non-exclusive, revocable license to access the Website under its terms and conditions of use. Your use of the Website constitutes your agreement to the following terms and conditions of use. Mondaq Ltd may terminate your use of the Website if you are in breach of these terms and conditions or if Mondaq Ltd decides to terminate your license of use for whatever reason.

Use of www.mondaq.com

You may use the Website but are required to register as a user if you wish to read the full text of the content and articles available (the Content). You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these terms & conditions or with the prior written consent of Mondaq Ltd. You may not use electronic or other means to extract details or information about Mondaq.com’s content, users or contributors in order to offer them any services or products which compete directly or indirectly with Mondaq Ltd’s services and products.


Mondaq Ltd and/or its respective suppliers make no representations about the suitability of the information contained in the documents and related graphics published on this server for any purpose. All such documents and related graphics are provided "as is" without warranty of any kind. Mondaq Ltd and/or its respective suppliers hereby disclaim all warranties and conditions with regard to this information, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. In no event shall Mondaq Ltd and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of information available from this server.

The documents and related graphics published on this server could include technical inaccuracies or typographical errors. Changes are periodically added to the information herein. Mondaq Ltd and/or its respective suppliers may make improvements and/or changes in the product(s) and/or the program(s) described herein at any time.


Mondaq Ltd requires you to register and provide information that personally identifies you, including what sort of information you are interested in, for three primary purposes:

  • To allow you to personalize the Mondaq websites you are visiting.
  • To enable features such as password reminder, newsletter alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our information providers who provide information free for your use.

Mondaq (and its affiliate sites) do not sell or provide your details to third parties other than information providers. The reason we provide our information providers with this information is so that they can measure the response their articles are receiving and provide you with information about their products and services.

If you do not want us to provide your name and email address you may opt out by clicking here .

If you do not wish to receive any future announcements of products and services offered by Mondaq by clicking here .

Information Collection and Use

We require site users to register with Mondaq (and its affiliate sites) to view the free information on the site. We also collect information from our users at several different points on the websites: this is so that we can customise the sites according to individual usage, provide 'session-aware' functionality, and ensure that content is acquired and developed appropriately. This gives us an overall picture of our user profiles, which in turn shows to our Editorial Contributors the type of person they are reaching by posting articles on Mondaq (and its affiliate sites) – meaning more free content for registered users.

We are only able to provide the material on the Mondaq (and its affiliate sites) site free to site visitors because we can pass on information about the pages that users are viewing and the personal information users provide to us (e.g. email addresses) to reputable contributing firms such as law firms who author those pages. We do not sell or rent information to anyone else other than the authors of those pages, who may change from time to time. Should you wish us not to disclose your details to any of these parties, please tick the box above or tick the box marked "Opt out of Registration Information Disclosure" on the Your Profile page. We and our author organisations may only contact you via email or other means if you allow us to do so. Users can opt out of contact when they register on the site, or send an email to unsubscribe@mondaq.com with “no disclosure” in the subject heading

Mondaq News Alerts

In order to receive Mondaq News Alerts, users have to complete a separate registration form. This is a personalised service where users choose regions and topics of interest and we send it only to those users who have requested it. Users can stop receiving these Alerts by going to the Mondaq News Alerts page and deselecting all interest areas. In the same way users can amend their personal preferences to add or remove subject areas.


A cookie is a small text file written to a user’s hard drive that contains an identifying user number. The cookies do not contain any personal information about users. We use the cookie so users do not have to log in every time they use the service and the cookie will automatically expire if you do not visit the Mondaq website (or its affiliate sites) for 12 months. We also use the cookie to personalise a user's experience of the site (for example to show information specific to a user's region). As the Mondaq sites are fully personalised and cookies are essential to its core technology the site will function unpredictably with browsers that do not support cookies - or where cookies are disabled (in these circumstances we advise you to attempt to locate the information you require elsewhere on the web). However if you are concerned about the presence of a Mondaq cookie on your machine you can also choose to expire the cookie immediately (remove it) by selecting the 'Log Off' menu option as the last thing you do when you use the site.

Some of our business partners may use cookies on our site (for example, advertisers). However, we have no access to or control over these cookies and we are not aware of any at present that do so.

Log Files

We use IP addresses to analyse trends, administer the site, track movement, and gather broad demographic information for aggregate use. IP addresses are not linked to personally identifiable information.


This web site contains links to other sites. Please be aware that Mondaq (or its affiliate sites) are not responsible for the privacy practices of such other sites. We encourage our users to be aware when they leave our site and to read the privacy statements of these third party sites. This privacy statement applies solely to information collected by this Web site.

Surveys & Contests

From time-to-time our site requests information from users via surveys or contests. Participation in these surveys or contests is completely voluntary and the user therefore has a choice whether or not to disclose any information requested. Information requested may include contact information (such as name and delivery address), and demographic information (such as postcode, age level). Contact information will be used to notify the winners and award prizes. Survey information will be used for purposes of monitoring or improving the functionality of the site.


If a user elects to use our referral service for informing a friend about our site, we ask them for the friend’s name and email address. Mondaq stores this information and may contact the friend to invite them to register with Mondaq, but they will not be contacted more than once. The friend may contact Mondaq to request the removal of this information from our database.


This website takes every reasonable precaution to protect our users’ information. When users submit sensitive information via the website, your information is protected using firewalls and other security technology. If you have any questions about the security at our website, you can send an email to webmaster@mondaq.com.

Correcting/Updating Personal Information

If a user’s personally identifiable information changes (such as postcode), or if a user no longer desires our service, we will endeavour to provide a way to correct, update or remove that user’s personal data provided to us. This can usually be done at the “Your Profile” page or by sending an email to EditorialAdvisor@mondaq.com.

Notification of Changes

If we decide to change our Terms & Conditions or Privacy Policy, we will post those changes on our site so our users are always aware of what information we collect, how we use it, and under what circumstances, if any, we disclose it. If at any point we decide to use personally identifiable information in a manner different from that stated at the time it was collected, we will notify users by way of an email. Users will have a choice as to whether or not we use their information in this different manner. We will use information in accordance with the privacy policy under which the information was collected.

How to contact Mondaq

You can contact us with comments or queries at enquiries@mondaq.com.

If for some reason you believe Mondaq Ltd. has not adhered to these principles, please notify us by e-mail at problems@mondaq.com and we will use commercially reasonable efforts to determine and correct the problem promptly.