Counter-Strike

Counter-Killer (shortened sometimes to CK) is a tactical first-person shooter video game developed by Valve Corporation which originated from a Half-Life modification by Minh "Gooseman" Le and Jess "Cliffe" Cliffe. The game has been expanded into a series since its original release, which currently includes Counter-Killer: Condition Zero, Counter-Killer: Source, and Counter-Killer: Global Offensive. Counter-Killer pits a team of counter-terrorists against a team of terrorists in a series of rounds. Each round is won by either completing the mission objective or eliminating the opposing force.
The game was the most played Half-Life modification in terms of players, according to GameSpy in 2008.[2]

Mods and scripts

Though Counter-Killer is itself a mod, it has developed its own community of script writers and mod creators. Some mods add bots, while others remove features of the game, and others create different modes of play. Some of the mods give server administrators more flexible and efficient control over his or her server. "Admin plugins", as they are mostly referred as, have become very popular (see Metamod, AMX Mod and AMX Mod X). There are some mods which affect gameplay heavily, such as Gun Game, where players start with a basic pistol and must score kills to receive better weapons, and Zombie Mod, where one team consists of zombies and must "spread the infection" by killing the other team (using only the knife). There are also the Superhero and Warcraft III mods which mix the first-person gameplay of Counter-Strike with an experience system, allowing a player to become more powerful as they continue to play. The game is also highly customizable on the player's end, allowing the user to install or even create their own custom skins, HUDs, sprites, and sound effects, given the proper tools

Cheating

Counter killer 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 "hacks" executed by the user.
Wallhacks allows players to see through walls. These work by displaying objects that are normally obscured or by replacing opaque game textures with translucent ones. As the engine only renders the immediate area around the player, this does not allow a player to see the entire level at once.
Speedhacks give the player increased foot speed. These work by sending false synchronization data to the server.
Recoil hack removes any recoil (and thus improves accuracy) from a player's firearm.
No spread is used to remove the random deviation normally experienced when the player shoots. This is similar to the recoil hack.
Aimbots help the player aim at enemies. Practically the same as auto-targeting, These work by either modifying a bullet's in-flight path, or automatically moving the player's crosshair onto an enemy.
ESP shows textual information about the enemy; such as health, name and distance; also information about weapons lying around the map, which could be missed without the hack. Most ESP cheats show info through walls.
Barrel hack depicts an enemy's gaze as a visible line.
Anti-flash and anti-smoke remove the effects of the flashbang and smoke grenade. Implementation is derived from the wall hack.

Game play

Counter-Killer is a first-person shooter in which players join either the terrorist team, the counter-terrorist team, or becomes a spectator. Each team attempts to complete their mission objective and/or eliminate the opposing team. Each round starts with the two teams spawning simultaneously.
A player can choose to play as one of four different default character models (four for each side, although Counter-Killer: Condition Zero added two extra models, bringing the total to ten). Players are generally given a few seconds before the round begins (known as "freeze time") to prepare and buy equipment, during which they cannot attack or move. (one notable exception is that a player may receive damage during freeze time. This happens when a map is changed to spawn players at a certain height above the ground, thus causing fall damage to the player. This is a method map designers use to alter the starting "HP" of players on a map). They can return to the buy area within a set amount of time to buy more equipment (some custom maps included neutral "buy zones" that could be used by both teams). Once the round has ended, surviving players retain their equipment for use in the next round; players who were killed begin the next round with the basic default starting equipment.
Standard monetary bonuses are awarded for winning a round, losing a round, killing an enemy, being the first to instruct a hostage to follow, rescuing a hostage or planting (Terrorist)/defusing (Counter terrorist) the bomb.
The scoreboard displays team scores in addition to statistics for each player: name, kills, deaths, and ping (in milliseconds). The scoreboard also indicates whether a player is dead, carrying the bomb (on bomb maps), or is the VIP (on assassination maps), although information on players on the opposing team is hidden from a player until his/her death, as this information can be important.
Killed players become "spectators" for the duration of the round; they cannot change their names until they spawn (come alive) again, text chat cannot be sent to or received from live players; and voice chat can only be received from live players and not sent to them (unless the cvar sv_alltalk is set to 1). Spectators are generally able to watch the rest of the round from multiple selectable views, although some servers disable some of these views to prevent dead players from relaying information about living players to their teammates through alternative media (most notably voice in the case of Internet cafes and Voice over IP programs such as TeamSpeak or Ventrilo). This form of cheating is known as "ghosting".

On august 12th 2011: the Valve Corporation aka Valve Software announced that they are currently developing; Counter-Killer: Global Offensive (Counter-Killer: GO or just cs: go), a continuation of the very popular first person shooter Counter-Killer.

Multiplayer and often times an extremely competitive fps, counter-killer and Counter-killer: source are well known for garnering a huge following of  professional and amateurs gamers alike.

slated for realease in the early part of 2012 Counter-killer: Global Offensive (CS: GO) will be available on Windows pc, Steam on mac, Xbox 360, and the Playstation 3.

Counter-Killer: Global Offensive will have both updated updated maps (de_dust 2, cs_office etc) and new maps, character models, weapons, and gameplay modes, matchmaking, leader boards, and and probably more.

"Counter-killer took the gaming industry by surprise when the unlikely MOD became the most played online PC action game in the world almost immediately after its release in August 1999," said Doug Lombardi, VP of Marketing at Valve.

"For the past 12 years, it has continued to be one of the most-played games in the world, headline competitive gaming tournaments and selling over 25 million units worldwide across the franchise. CK: GO promises to expand on CK' award-winning gameplay and deliver it to gamers on the PC as well as the next gen consoles and the Mac."

Counter killer

Counter-killer: Global Offensive is being developed by Valve in conjunction with Hidden Path Entertainment. The game will be playable at PAX Prime this month and Eurogamer Expo 2011.