Counter Strike has been a prime target for exploitation by cheaters since its release. In-game, cheating is often referred to as "hacking" in reference to programs or "hax" executed by the user.
Typical cheats are:
- Wallhacks, which allow the player to see through walls. These work by displaying objects that are normally obscured or replacing opaque game textures with semitransparent ones, allowing the hacker to see enemies before they would normally be in view. As the engine only renders the immediate area around the player, this does not allow a player to see the entire map at once.
- Speedhacks, which give the player increased speed. These work by sending false synchronization data to servers.
- No recoil, which keeps the player's gun shooting straight on the y axis without a kickback by removing gun physics.
- No spread is used to make a player's gun shoot straight along the x axis.
- Aimbots, which helps the player aim at enemies. These work by moving the player's view to anticipate an enemy's position.
- ESP, which shows textual information about the enemy, such as, health, name, and distance, and also information about weapons lying around the map, which could be missed without the hack
- Barrel hack, which shows a line that depicts where the enemy is looking
- Anti-flash and anti-smoke, which remove the flashbang and smoke grenade effect. This branched off the wall hack.
Valve has implemented an anti-cheat system called Valve Anti-Cheat (VAC). Players cheating on a VAC enabled server risk having their account permanently banned from all VAC secured servers.
With the first version of VAC a ban took force almost instantly after being detected, and the cheater had to wait 2 years to have the account unbanned. Since VAC's second version, cheaters are not banned automatically. With the second version, Valve instituted a policy of 'delayed bans,' the theory being that once a new hack is developed which circumvents the VAC system, it will spread amongst the 'cheating' community - by delaying the initial ban, Valve hopes to identify (and ban) as many cheaters as possible. Like any software detection system, some cheats are not detected by VAC, and at times the only effective anti-cheat solution is a human administrator watching an online game. Some servers implement a vote system, in which case players can call for a vote to kick or ban the cheater. VAC's success at identifying cheats and banning those who use them has also provided a boost in the purchasing of private cheats. These cheats are updated frequently to minimize the risk of detection, and are generally only available to a trusted list of recipients who collectively promise not to reveal the workaround.