Counter-Strike is a popular video game that modifies the multiplayer aspects of Half-Life, making it more team-oriented and providing players with an experience similar to what a real counter-terrorist or terrorist unit would go through. Players join either the Counter Terrorist team or the Terrorist team as they battle against each other in various mission scenarios. The goal of each round is to eliminate all opposing forces or complete objectives while also managing resources such as ammunition, money and health. With its fast pace and intense gameplay, Counter Strike has become one of the most popular online games today.

Counter-Strike: Global Offensive is a popular first-person shooter video game released in 2012. It is the fourth installment of the Counter-Strike franchise and builds upon its predecessor by introducing new maps, characters, weapons, and updated versions of classic CS content. The game has become one of the most popular online shooters with millions of players around the world competing in different game modes such as competitive ranked matches or casual ‘deathmatch’ style games. Players can choose from a variety of weapons to customize their loadouts for each match and use tactics to outsmart their opponents in order to win rounds.

Call of Duty: Black Ops, developed by Treyarch, is the next installment in the Call of Duty franchise. It is rumored to be a first-person shooter set during the Cold War period. The game will feature an extensive single player campaign and competitive multiplayer modes as part of its core gameplay experience. This will be the second time in the series that it has gone back to a period prior to World War II, with 2008's Call Of Duty: World At War being set during WW2. With Black Ops, players can expect new weapons and technology from this era along with classic elements from previous entries in the series such as zombies mode and online play for up to 16 people simultaneously.

Counter-Strike: Source is a popular video game from Valve that uses the Source engine. It has recreated maps from Counter-Strike 1.6, such as Office, Havana, Italy, Aztec, Chateau and more with new textures and improved buildings and scenery. Objects in these levels react realistically to the physics engine of the Source engine. The game can be downloaded through Valve's Steam service with Half-Life 2 included in the package.

Call of Duty: Black Ops II is a first-person shooter video game set in a near-future version of the Cold War. Players take on the role of an elite soldier tasked with thwarting Raul Menendez, a diabolical villain who has hijacked US military infrastructure to advance his own agenda and bring the world to the brink of destruction. The game features state-of-the-art technology and next-gen robotics, allowing players to use advanced weapons and equipment in order to save humanity from total annihilation.