Digital rights management (DRM)
Digital Rights Management (DRM) is a method in which digital products such as games, music and films can be controlled with the aim of reducing copyright infringement, also known as piracy.
- The Big List of 3rd Party DRM on Steam
- DRM article on Wikipedia
- SecuROM Website (Including removal information)
- Defective By Design - DRM Opposition
- Steamworks DRM Website
DRM-free refers to games which can be played and copied without restriction.
 Forms of DRM
DRM can come in many forms, not all of them exclusive to each other.
 Physical Check
Many PC games before 2000 included codes hidden inside manuals and other items included in retail packages. This might deter some people from making simple copies of games, as installation would require copies of the physical checks (of manuals or of other devices).
For example, The Secret of Monkey Island originally included a 'Dial-a-Pirate' wheel. A point in the game would require the player to match up two halves of the faces and to read off a certain code that was revealed. Once one span the two interlocking wheels into the correct position, the correct answer would be revealed.
 Disc Check
Some games require a retail CD or DVD of the game to be present to run, regardless of whether the entire game content is installed on the hard drive.
Part of the game may not be on the disc, requiring a download of the rest of the games content in order to work.
 Disc Copy Protection
There are a variety of means used to prevent making burned copies of retail discs. These include purposefully putting defects on the disc and adding hidden software that is installed on disc insertion that interferes with burning software and disc burners.
 Serial Key
The simplest form of DRM is Serial key, also known as a CD-key. The game comes with a code, usually printed in the case or on the back of the manual, that the user inputs during install.
A serial key typically can only be used by one person at a time, and some games compare keys during multiplayer games to ensure copying has not occurred. Some games (such as Starcraft) allow "spawning", where a single key can be used multiple times, but only unlocking limited features on the second and subsequent computers. In the case of Starcraft, spawning allowed multiplayer games to be played with a single key with no CD check, as long as the host of the game was using the full version with the same key.
 Unlock Codes
Some games may not function or have limited features until unlocked with a code, which must be purchased from the developer. This is similar to the serial key method, except that the code is provided separately from the software in this case. Some games use this to allow limited "demo sharing" while requiring all users to purchase the game.
 Always Online
An example of Always online is Diablo III, which requires one to be connected to Battle.net, even to access single player content. This is in stark contrast to Diablo II, which had no restrictions for single player gaming.
Another notorious example is Uplay, Ubisoft's always online DRM platform.
 Online Activation
This form of DRM enforcement requires you to notify the rights holders of a game after installation, typically using Internet activation. This is often paired with identifying information about your computer. Typically this is used in conjunction with a CD-key or other identifier, but not always.
 Installation Limits
This is usually paired with other forms of DRM or copy protection. Some games use a variety of means to prevent multiple installs of a game, giving a set limit to how many times a game can be installed. For example, Batman: Arkham Asylum requires Internet activation after installing, but will only activate 4 times. Uninstalling the game usually does not restore an "install slot", but some games provide a deactivation tool that allows additional installs. Further, sometimes game companies will reset install counters on a case-by-case basis if asked, but not usually.
 Account-based DRM
Services such as Steam, and games such as World of Warcraft pair a game with an online account linked to an email address, allowing you to use multiple computers, but are only able to be used by one person.
 DRM Software
 Valve Steam
Steam ties all games bought through its service, or using the Steamworks API, to a user account and requires an online connection to install and play (although most games can be played offline once activated). Many Steam games include additional DRM, such as Games for Windows Live.
 EA Origin
A relatively new content delivering/DRM system that has received negative attention due to its intrusive anti-piracy measures.
One of the most common and longest enduring forms of DRM, SecuROM uses a variety of methods to verify the integrity of a game, as well as preventing disc burning of protected material. It is used on both physical media and digital downloads. SecuROM installs silently on a computer, and monitors certain system behavior, preventing the game from running if it finds anything suspicious. It must be manually removed from the computer, there is no uninstall option (there is a removal tool on the SecuROM website) if you decide to stop using the game and no longer want the DRM.
Another older DRM, StarForce has changed several times over the years. StarForce provides many of the functions of other DRM software, but installs itself as a driver on your computer. This along with a number of purported hardware and software issues made StarForce very controversial, and lead to a decline in its use due to user complaints.
 Games for Windows Live
Designed by Microsoft as a way to provide multiplayer gaming for both Xbox and Windows, GfWL is an online platform where the game is linked to an account (online or offline), and multiplayer (and in many cases single player) games require you to log in to a server. The service is not globally available, meaning you cannot play games that require the service if you do not live in one of the supported countries.
Tages, like StarForce, installs itself as a driver on your computer. Tages uses multiple methods to prevent copying. Like SecuROM, Tages provides a removal tool.
 Ubisoft Uplay
Ubisoft's DRM software was in July 2012 found to have a severe security vulnerability. A browser plugin that is installed silently and without consent allows websites to open programs and modify the contents of the user's hard drive. It has since been patched. Some Ubisoft games also require a constant internet connection, even for single player games.
 DRM Removal
DRM is required by many games, which will not run if the DRM is removed. Removing DRM while these games are installed is not recommended...and in some cases, running the game will reinstall the DRM. Circumventing DRM is illegal in some countries (unless you have the developer/publisher's consent). However, there are circumstances where it is possible, legal, and advisable to remove DRM.
If you uninstall all software related to the DRM, the DRM can typically be removed safely. Many DRM companies provide a removal tool, other programs can be uninstalled directly.
Occasionally a developer will remove DRM from a game with a patch after a long period of time. Patching the game in these cases is a legitimate way of running the game without DRM. For example, Civilization IV: Beyond The Sword was eventually patched to remove DRM and CD checks from the game, and the Civilization IV series was re-released as a DRM-Free game soon after.
 DRM and Second-Hand Software
Used software is very susceptible to anti-piracy measures. A number of problems can occur when buying used games, due to DRM or copy protection.
- Lost Code Wheels/Manuals/physical DRM. Older games, such as Pool of Radiance, require a physical tool to progress in the game. Used copies do not always include these materials, and online replacements may be difficult to find, rendering the game useless.
- Missing, Registered, or Banned Keys. Games that require an installation key may not always have the key with them when used. The game cannot be installed without the key. In other cases, games such as World of Warcraft (prior to the free version) could not be effectively bought used, because they had one-time key usage. Another potential problem is buying a used game, and finding the multiplayer or online features of the game disabled due to actions of the previous owner.
- Activation. Related to the registered keys problem, some software requires online activation, and used copies may fail activation because of this if they have already been played. Activation effectively makes games unsuitable for resale or transfer.
DRM presents an issue for long term games collectors as it can lead to games becoming completely locked out as CD-keys are lost, studios close or withdraw support, or online services discontinued. This can be resolved by studios issuing a patch that removes the DRM, though not all studios do this.
Another historic problem with DRM software is unexpected hardware and software problems. For example, early versions of StarForce sometimes caused strange behavior in optical drives, occasionally making Windows unable to detect and access CD-ROMs.
Online activated DRM, present in games such as Spore means that the game becomes useless when support for the servers is withdrawn. Existing installations may continue to function, but new installations will no longer function.
DRM is rarely disclosed on packaging, and is installed silently on computers, sometimes without user consent. Many people as an effect do not know they have DRM software installed on the computer. Some DRM installs in critical system areas (such as "Ring-0 DRM"), a behavior typically used by malicious software due to the control it allows over a system.
DRM also has potential to malfunction, flagging a legitimate game as pirated. For instance, The Battle For Middle Earth had a copy protection system that looked for signs of pirating that was known to trigger on legitimate installs, causing all the characters to die randomly. The only fix was to uninstall and reinstall the game.
The nature of DRM also makes resale of computer software difficult, in some cases impossible, which conflicts with the First Sale Doctrine many nations follow.
Purposefully deactivating or disabling DRM without permission of the rights holder may be illegal in some countries.
DRM tends to stay on a computer after the related software is removed, sometimes requiring a special tool to remove. Most people are unaware that the DRM remains on their computer. Removing DRM while a game is installed typically breaks the game.
Online-based DRM can be revoked by any reason. Also, online-based DRM has potential for errors and is susceptible to abuse from piracy. For instance, pirated/keygen produced install keys can be registered, meaning the legitimate keys are flagged as invalid. Some games have a history of key banning for trivial reasons. The problem of falsely revoked keys is particularly noticeable on Spore.
DRM may contain security vulnerabilities, as revealed in the UPlay DRM backdoor.