Valve Anti-Cheat

Valve Anti-Cheat, abbreviated to VAC, is a proprietary anti-cheat solution developed and maintained by Valve Corporation as a component of the Steam platform. Although predating Steam, VAC has been fully adapted to its network and, since the release of VAC2, has seen considerable success in the constant battle against cheating in online games.

VAC was first released with Counter-Strike 1.4 in 2002,

Others charge the system (delayed bans or not) with existing to make Valve money,Fact|date=February 2007 on the basis that cheaters will buy another copy of the game in order to continue cheating rather than desist. While it is not unknown for cheaters to steal copies from shops in order to do this, the purchasing of new ones has only been reliably observed in those caught and reformed, mainly through their apologetic posts on the [http://forums.steampowered.com/forums/forumdisplay.php?s=&forumid=35 Steam User Forums] .

Another criticism is that delayed bans increase the public's exposure to cheaters, and may drive otherwise innocent parties to install cheats of their own.

False-positive detections

Those that have been caught by VAC also criticise it, usually with the claim that it has made a false positive. Here a distinction must be made between false positives caused by incorrect detection, and grey-area false positives caused by correctly-identified code modifications which do not actually offer an unfair advantage.

*There are three recorded instances of incorrect detections, all under VAC1 and all quickly rescinded and reversed. These were:
*#Physical RAM corruption.Fact|date=February 2007
*#The effect of running the VAC-protected game through the WineX Windows emulator for Linux.cite web|url=http://www.csnation.net/viewnews.php/6278/|work=CS Nation|title=WineX and VAC|date=10 July 2003|accessdaymonth=28 July |accessyear=2006]
*#An apparent server-side glitch on 2004-04-01.cite web|url=http://www.csnation.net/comments.php?id=7083|title=VAC Bans Ramp Up|work=CS Nation|date=15 April 2004|accessdaymonth=28 July |accessyear=2006]
*There are three recorded instances of the "benign cheats" described above triggering bans. These were:
*#VAC1: "HLamp", which allowed the user to control Winamp from the game's interface. Detection later reversed, and all bans caused by it rescinded.
*#VAC2: The "X-Spectate" tool, which allowed server administrators to enable a wallhack effect while spectating to help decide if another player was doing the same. Later downgraded to a kick from the server, but bans not rescinded.
*#VAC2: The single-player Half-Life modification " [http://paranoia.level-design.ru/index_eng.htm Paranoia] ", which made changes to the engine's renderer that propagated to multi-player games.cite web|url=http://forums.steampowered.com/forums/showthread.php?t=710692|title=VAC ban because of Paranoia mod!|date=2008-08-04|accessdate=2008-09-18]

Cheats may be hidden inside otherwise legitimate mod or skin downloads that are created to maliciously get innocent people banned. Since the source of a cheat installed on a computer cannot be proven, bans due to this are never rescinded.

ee also

*Cheating in online games
*PunkBuster
*Warden (software)
*Steam (content delivery)

References