question: how do video games know they are a pirated copy
comment: From /u/rsb_david "The below items are three ways in which games/studios can and do track if a game copy is pirated or not. 1. A studio will release a pirated copy on common locations and have modified code to either send a packet to a remote server or just screw with the person who obtained the copy illegally. 2. The game will require online connectivity and have multiple layers to check for pirating. For example, a game may do the first check upon loading your computer and a parent application like Steam or UPlay. A second check might be when you start the actual game. A third check may occur every 3200 - 4450 game cycles while the game is running. A fourth check will be a static period in which the client has to make contact with the outside network. If at any point the game can not validate your authorization, it may notify the studio, corrupt your save files, or corrupt the game. Each time the game update, a list of remote servers changes as well so you can't just block the IP in your firewall. Some studios are talking with social media sites to route through their network so that you will lose access to something like Facebook if you try to block a remote verification server for your pirated game. 3. Installation unique identifier tracking. A company may generate a custom install key per user which is then embedded into the compiled application in a way which is not obvious. The studio might randomly download pirated copies and pull the key to trace the original source. __ Essentially, check the terms of service/EULA/privacy policies for how your data is tracked and how a company may track copyright offenders."
passages: BULLET::::- As a more satirical nod to the issue, if the thriller-action game "Alan Wake" detects that the game is cracked or a pirated copy, it will replace tips in loading screens with messages telling the player to buy the game. If a new game is created on the copied game, an additional effect will take place. As a more humorous nod to "piracy", Alan Wake will gain a black Eyepatch over his right eye, complete with a miniature Jolly Roger.
   BULLET::::- "Nevermind", a puzzle game for the Amiga, contained code that caused an unlicensed version of the game to behave as a demo. The game would play three levels sampled from throughout the game, and then give the message "You have completed three levels; however there are 100 levels to complete on the original disc."
   BULLET::::- In "" a character named Zoe will tell the player outside the room containing the balloon to Midday Garden Home and several other areas that the player is using an unlicensed copy. This conversation purposely corrupts data. When corrupted, the game would not only remove stray gems and the ability to progress in certain areas but also make the final boss unbeatable, returning the player to the beginning of the game (and removing the save file at the same time) after about 8 seconds into the battle.
   BULLET::::- Bohemia Interactive Studio developed a unique and very subtle protection system for its game "". Dubbed FADE, if it detects an unauthorized copy, it does not inform the player immediately but instead progressively corrupts aspects of the game (such as reducing the weapon accuracy to zero) to the point that it eventually becomes unplayable. The message "Original discs don't FADE" will eventually appear if the game is detected as being an unauthorized copy.
   BULLET::::- "Zork" games such as "Beyond Zork" and "Zork Zero" came with "feelies" which contained information vital to the completion of the game. For example, the parchment found from Zork Zero contained clues vital to solving the final puzzle. However, whenever the player attempts to read the parchment, they are referred to the game package.
  
  BULLET::::- The Lenslok system used a plastic prismatic device, shipped with the game, which was used to descramble a code displayed on screen.
   Code inserted into content can add information to the output that specifically identifies the player, and in a large-scale distribution of the content, can be used to trace the player. This may include the fingerprint of a specific player.
  
  Section::::Weaknesses.
   Section::::Comparative analysis about inclusion of copyright protection.:United States of America.:Subtractive Approach Test.
  
  "Nichols v. Universal Pictures" laid out the following test for copyrighted material which contains both copyrightable and public domain material. The Case lays down 3 steps to be followed to ascertain copying:
  
  BULLET::::1. The allegedly infringed work is analyzed to determine the parts that are protected,
  
  BULLET::::2. The unprotected parts are subtracted, and
  
  BULLET::::3. The fact finder examines significant similarities between what remains of the allegedly infringed work and the allegedly infringing work.
   BULLET::::- "Metal Gear Solid" and many other computer games require a piece of information from the game's jewel case for the player to progress after a certain point, making unauthorized copies effectively worthless without the original jewel case; however, in the present day, said information can be easily be found on the Internet.
  
  BULLET::::- Microsoft removes Windows Vista and Microsoft Office from various torrent trackers.
  
  BULLET::::- Certain SNES games such as "Super Mario All Stars" and "Donkey Kong Country" may sometimes show warning screens, usually caused by dirty or damaged cartridges or use of third-party peripherals.
   BULLET::::- The "IndyCar Series" (2003 video game) also utilizes FADE technology to safeguard against piracy by making races very difficult to win on a pirated version. The penultimate section of the game’s manual states:
  
  "Copying commercial games, such as this one, is a criminal offense and copyright infringement."br
  
  "Copying and re-supplying games such as this one can lead to a term of imprisonment."br
  
  Think of a pirated game as stolen property.br
  
  "This game is protected by the FADE system. You can play with a pirated game- but not for long. The quality of a pirated game will degrade over time."br
   Sometimes only partial compliance with license agreements is the cause. For example, in 2013, the US Army settled a lawsuit with Texas-based company Apptricity, which makes software that allows the army to track their soldiers in real time. In 2004, the US Army paid US$4.5 million for a license of 500 users, while allegedly installing the software for more than 9000 users; the case was settled for US$50 million. Major anti-piracy organizations, like the BSA, conduct software licensing audits regularly to ensure full compliance.
   "Purchase only genuine software at legitimate stores."
  
  BULLET::::- "" contained code that disabled Batman's glider cape, making some areas of the game very difficult to complete and a certain achievement/trophy impossible to unlock (gliding continuously for over 100m).
   BULLET::::- "EarthBound" is well-documented for its extensive use of checksums to ensure that the game is being played on legitimate hardware. If the game detects that it is being played on a European SNES, it refuses to boot, as the first of several checksums has failed. A second checksum will weed out most unauthorized copies of the game, but hacking the data to get past this checksum will trigger a third checksum that makes enemy encounters appear much more often than in an authorized copy, and if the player progresses through the game without giving up (or cracks this protection), a final checksum code will activate before the final boss battle, freezing the game and deleting all the save files. A similar copy protection system was used in "Spyro: Year of the Dragon", although it only uses one copy protection check at the beginning of the game (see below).
   In 2002, the Mendocino Game Company ceased producing "Pirateer". The designer of the game, Scott Peterson, unsuccessfully sued board members for misappropriating trade secrets, breaching their fiduciary duty and conspiring to seize control of the company. The board members counter-sued and, in 2009, a Mendocino County jury ordered Scott Peterson to pay $791,000 to investors and members of the company’s board of directors in restitution and punitive damages for defamation.
  
  Section::::Critical reception.
   BULLET::::- The Atari version of would have the player's character attacked by two unbeatable "FBI Agents" if it detected a cracked version. The FBI agents would also appear when restoring a save which was created by such a version, even if the version restoring the save was legal.
   Some software that implements online registration extends this with a process commonly known as "phoning home". In this case, the software, either each time it is used or at some preset interval such as monthly, makes another connection back to the registration server. It does this to check in with the server to see if the serial number it is using has been determined to be one that is being used to install in many places. Serial numbers that have been identified as "pirated" (illegally distributed) are added to a blacklist on the server, a process referred to as being "burned". Burned serial numbers cannot be used to install or activate the product. Serial number lists are available on the internet that include a large number of valid registration codes for many software titles. It is common for software manufacturers to seek out these lists and invalidate the serial numbers that appear on these lists. This discourages individuals from giving out their registration codes for fear that this code will later be invalidated, disabling the original install of the software the next time that it "phones home".
   Software can contain trade secrets, which provide a competitive advantage to a business. To determine trade secret theft, the same tools and processes can be used to detect copyright infringement. If code was copied without authority, and that code has the characteristics of a trade secret—it is not generally known, the business keeps it secret, and its secrecy maintains its value to the business—then the copied code constitutes trade secret theft.
   BULLET::::- In "", if the game code detects what it believes to be an unauthorized copy, an invincible scorpion-like monster is spawned in the beginning of the game with high speeds, melee attacks, and attacks from a range with twin chainguns making the game extremely difficult and preventing the player to progress further. Also in the level "Under the Iron Cloud", the player's character will spin out-of-control looking up in the air.
   Trade secret theft can also involve the taking of code functionality without literally copying the code. Comparing code functionality is a very difficult problem that has yet to be accomplished by any algorithm in reasonable time. For this reason, finding the theft of code functionality is still mostly a manual process.
  
  Section::::Patent infringement.
   Many games use the "code checksumming" technique to prevent alteration of code to bypass other copy protection. Important constants for the game - such as the accuracy of the player's firing, the speed of their movement, etc. - are not included in the game but calculated from the numbers making up the machine code of other parts of the game. If the code is changed, the calculation yields a result which no longer matches the original design of the game and the game plays improperly.
   BULLET::::- An unauthorized copy of "Pokémon Black and White" and their sequels will run as if it was normal, but the Pokémon will not gain any experience points after a battle. This has since been solved by patching the game's files.
  
  BULLET::::- If "Ace Attorney Investigations 2" detects an illegitimate or downloaded copy of the game, it will convert the entire game's text into the game's symbol based foreign language, Borginian, which cannot be translated in any way.
   BULLET::::- On a copied version of the original PC version of "Postal", as soon as the game was started, the player character would immediately shoot himself in the head.
   To limit the number of free copies, the disc typically comes with a single-use code to authenticate a computer over the Internet. Often the authentication code may have an expiration date, rendering the copy invalid if it the redemption code is fulfilled after that time. In common practice, most codes have remained available to redeem well after the printed expiration date, in order to keep customer goodwill and avoid complaints about the inability to redeem a code for a title which continues to sell older stock. Over time, this became the preferred method of digital copy validation over including a disc digital file in the package.
   BULLET::::- "The Secret of Monkey Island" offered a rotating wheel with halves of pirate's faces. The game showed a face composed of two different parts and asked when this pirate was hanged on a certain island. The player then had to match the faces on the wheel, and enter the year that appeared on the island-respective hole. Its "sequel" had the same concept, but with magic potion ingredients. Other games that employed the code wheel system include "Star Control".
   Past methods of code comparison included hashing, statistical analysis, text matching, and tokenization. These methods compared software code and produced a single measure indicating whether copying had occurred. However, these measures were not accurate enough to be admissible in court because the results were not accurate, the algorithms could be easily fooled by simple substitutions in the code, and the methods did not take into account the fact that code could be similar for reasons other than copying.
  
  Section::::Robert Zeidman.
   FADE
  
  FADE (or "DEGRADE") is digital rights management software developed by Codemasters. It operates by detecting if a game has been pirated, and initially allows the player to use the game normally. It then gradually degrades certain game features over a time, eventually rendering it unplayable.
  
  Section::::How it works.
  