November 8, 2000 (retail)
Counter-Strike (originally marketed as Half-Life: Counter-Strike) is a multiplayer first-person shooter initially created by Minh Le and Jess Cliffe as a mod for Half-Life. By the fourth beta, the Valve Corporation began assisting the two developers and ultimately offered them jobs. Both of them accepted, and the rights for the game were acquired by Valve. After over a year of public beta testing, the retail version of Counter-Strike was published by Sierra Entertainment on November 8, 2000 for Microsoft Windows. Since the creation of the franchise, various sequels and spinoffs have been created such as Counter-Strike: Condition Zero, Counter-Strike: Source, and the latest in the series, Counter-Strike: Global Offensive.
- Main article: Counter-Strike Beta
The game started out as a Half-Life modification on the Goldsource engine. It went through seventeen different iterations and was eventually released as a standalone game. Throughout this time, it grew in popularity and became one of the most popular first-person shooters of all time.
- Main article: Counter-Strike patches
On November 8, 2000, the game was ushered out of the beta phase and officially released as a fully licensed product. Even afterwards, development was ongoing and saw the release of several very large patches. The most recent, 1.6, is now used as a title to differentiate the original game from the rest of the series. With the launch of Steam on September 12, 2003, these large patches became unnecessary and were replaced with smaller updates.
- Main article: Gameplay
Its fast-paced and team-oriented gameplay has stayed relatively the same throughout the years. In it, two teams, the Counter-Terrorists and the Terrorists, fight to complete an objective or eliminate the opposing team. Although basic, it is considered one of the most revolutionary online games of all time. The original Counter-Strike came exclusively with multiplayer, without even computer-controlled players. Over time, however, several server-side modifications have added bots for in-game use .
Counter-Strike has been praised worldwide for its highly rewarding multiplayer. There are three official scenarios (game modes), each with their own teams, objectives, and maps. The Counter-Terrorists ("the good guys") face off against the Terrorists ("the bad guys").
Counter-Strike is considered one of the most influential games of all time. It's still the most popular Half-Life mod and even one of the most popular PC games. As of December 3, 2008, Counter-Strike has sold over 4.2 million retail copies, more than any other Valve game besides Half-Life and its sequel, Half-Life 2.  It scored an 88 on Metacritic, based on the reviews of eleven critics.