Like the previous games in the series, Global Offensive is an objective-based multiplayer first-person shooter. Each player joins either the Terrorist or Counter-Terrorist team and attempts to complete objectives or eliminate the enemy team. The game operates in short rounds that end when all players on one side are dead or a team's objective is completed. For most game modes, once a player dies, they must wait until the round ends to respawn.

Players purchase weapons and equipment at the beginning of every round with money awarded based on their performance. Completing objectives or killing enemies earns the player money while negative actions, like killing a teammate or hostage, takes money away from the player. In addition, when a round ends all players receive some amount of money, with players on the winning team receiving substantially more.

Counter-Strike: Global Offensive adds new weapons and equipment not seen in previous installments, most notably the firebomb for each side. These temporarily cover a small area in fire, dealing damage to anyone passing through.

Cosmetic items, such as weapon finishes, were added post-release.

Game modes
Currently, Global Offensive features five game modes for online play:

Classic Casual and Competitive: Counter-Strike‍ '​s most well-known game mode, both involving Bomb Scenario and Hostage Scenario missions. At the start of each round, players can purchase weapons and gear with money earned from various actions, from assisting on kills to completing objectives. Regardless of mission type, a round ends when one team completes an objective, eliminates the other team, or lets the timer run out. If the timer runs out before one of these objectives are completed, the team which did not need to complete an objective wins.
Bomb Scenario: the Terrorists must plant a C4 explosive at one of two designated bombsites and protect it until its countdown finishes and detonates; the Counter-Terrorists must prevent the bomb from exploding, either ensuring that the terrorist team does not plant it or defusing it once it is planted.

Hostage Scenario: the Counter-Terrorists must rescue hostages from the Terrorists, and bring them to an extraction point; the Terrorists must prevent the hostages from escaping. If a Terrorist or Counter-Terrorist attempts to kill hostage, they will suffer a heavy cash penalty. An update later changed how Counter-Terrorists rescue hostages: instead of leading them around, players must carry one hostage at a time to the extraction point.
Arms Race: a deathmatch-based mode where each player is rewarded for each kill with a new weapon, with the first player to get a kill with every weapon in a predetermined set winning the game.
Demolition: a round-based mode that removes weapon and equipment purchasing, instead rewarding players who manage at least one kill by giving the next weapon in a predetermined set of weapons. After a second kill with that weapon the players are also rewarded a grenade along with their new weapon for the next round.

Deathmatch (added on November 12, 2012): a mode consisting of 10-minute matches. Players must gain the highest possible score by earning kills with different weapons or desired weapons. The number of points from a kill depend on the weapon. Players may also take advantage of bonus timers for different weapons, using them to score extra points. Like in Arms Race, players automatically respawn after getting killed, but also when they choose to respawn with bonus weapons.

Global Offensive also offers two offline modes: Offline with Bots, which offers the same game modes with AI-controlled bots; and a Weapons Course, a single player map serving as a tutorial and a training mode.

Online play
Global Offensive supports matchmaking and leaderboards for all online game modes, provided by Steam. The provided online service offers the ability to filter by game modes, maps and a built-in Steam friend system. Valve also employs Valve Anti-Cheat, which can automatically remove and ban players from the Valve online network. To match players of similar skill levels for an enjoyable experience, the game uses a heavily modified version of Elo rating system. The PC version of Global Offensive also supports private dedicated servers that the player may connect to through the community server menu in-game. These servers may be heavily modified and can be completely different from the base game.

Development
Global Offensive began as a port of Counter-Strike: Source to Xbox Live Arcade by Hidden Path Entertainment. During the development Valve saw the opportunity to turn the port into a full game and expand on Counter-Strike‍ '​s gameplay. Global Offensive began development in March 2010 and was revealed to the public on August 12, 2011.

The closed beta started on November 30, 2011, and was initially restricted to around ten thousand people who received a key at events Valve attended to showcase Global Offensive. After issues such as client and server stability were addressed the beta was opened up to progressively more and more people (approximately 100,000 beta keys were given out as of July 4, 2012), until the beta became open for anybody to join and play.[25] Before the public beta Valve invited professional Counter-Strike and Counter-Strike: Source players to play-test the game and give feedback.

At E3 2012, Valve announced that Global Offensive would be released August 21, 2012 on all platforms, with an open beta starting roughly a month before that. It was never released on the PlayStation Network in Europe.

Post-release
Global Offensive initially launched with four game modes: Classic Casual, Competitive, Demolition, and Arms Race, and several official maps for each of the game modes. The Deathmatch game mode as well as more official maps, some user-made, were added post-release. The mechanics for the Hostage Scenario were revamped post-release. New weapons, such as the CZ-75 Auto, were added post release. The statistics for the weapons and the layout of the maps were modified post-release for competitive balance.

Cosmetic items, such as weapon finishes, were added on August 13, 2013 in a major update named the "Arms Deal" update. Most cosmetic items are received via game-end drops and opening virtual crates with keys that can be bought through microtransactions, similar to the item drop systems in Team Fortress 2 and Dota 2. These items can also be traded between players through the Steam trading system or the Steam Community Market.

Valve enabled Steam Workshop support for Global Offensive, allowing users to upload user-created content, such as maps, weapon finishes, and custom gameplay scenarios, and subscribe to user-uploaded maps to download them. In previous versions of Counter-Strike, players had to download maps through third party sites or while attempting to connect to a server. The Steam Workshop is controlled by Valve, and they reserve the right to remove content.

Valve supported community map-makers in the form of "operations", which act like expansion packs and require players purchase "operation passes" to play community made maps on Valve's official servers (this does not affect the map being played on community servers), with the exception of Operation Breakout which doesn't require the player to buy a pass. Each operation only lasts a certain amount of time before a new operation is released, requiring players to buy a new pass. A portion of the income generated through pass sales is given to the creators of the maps.

Popular user-created weapon finishes will have the chance to be added in the game as official cosmetic items in updates, where they can be received in virtual crates. A portion of the income generated through the sale of keys in order to receive these finishes is given to the creators of the weapon finishes.

Like the previous games in the series, Global Offensive is an objective-based multiplayer first-person shooter. Each player joins either the Terrorist or Counter-Terrorist team and attempts to complete objectives or eliminate the enemy team. The game operates in short rounds that end when all players on one side are dead or a team's objective is completed. For most game modes, once a player dies, they must wait until the round ends to respawn. Players purchase weapons and equipment at the beginning of every round with money awarded based on their performance. Completing objectives or killing enemies earns the player money while negative actions, like killing a teammate or hostage, takes money away from the player. In addition, when a round ends all players receive some amount of money, with players on the winning team receiving substantially more. Counter-Strike: Global Offensive adds new weapons and equipment not seen in previous installments, most notably the firebomb for each side. These temporarily cover a small area in fire, dealing damage to anyone passing through. Cosmetic items, such as weapon finishes, were added post-release. Game modes Currently, Global Offensive features five game modes for online play: Classic Casual and Competitive: Counter-Strike‍ '​s most well-known game mode, both involving Bomb Scenario and Hostage Scenario missions. At the start of each round, players can purchase weapons and gear with money earned from various actions, from assisting on kills to completing objectives. Regardless of mission type, a round ends when one team completes an objective, eliminates the other team, or lets the timer run out. If the timer runs out before one of these objectives are completed, the team which did not need to complete an objective wins. Bomb Scenario: the Terrorists must plant a C4 explosive at one of two designated bombsites and protect it until its countdown finishes and detonates; the Counter-Terrorists must prevent the bomb from exploding, either ensuring that the terrorist team does not plant it or defusing it once it is planted. Hostage Scenario: the Counter-Terrorists must rescue hostages from the Terrorists, and bring them to an extraction point; the Terrorists must prevent the hostages from escaping. If a Terrorist or Counter-Terrorist attempts to kill hostage, they will suffer a heavy cash penalty. An update later changed how Counter-Terrorists rescue hostages: instead of leading them around, players must carry one hostage at a time to the extraction point. Arms Race: a deathmatch-based mode where each player is rewarded for each kill with a new weapon, with the first player to get a kill with every weapon in a predetermined set winning the game. Demolition: a round-based mode that removes weapon and equipment purchasing, instead rewarding players who manage at least one kill by giving the next weapon in a predetermined set of weapons. After a second kill with that weapon the players are also rewarded a grenade along with their new weapon for the next round. Deathmatch (added on November 12, 2012): a mode consisting of 10-minute matches. Players must gain the highest possible score by earning kills with different weapons or desired weapons. The number of points from a kill depend on the weapon. Players may also take advantage of bonus timers for different weapons, using them to score extra points. Like in Arms Race, players automatically respawn after getting killed, but also when they choose to respawn with bonus weapons. Global Offensive also offers two offline modes: Offline with Bots, which offers the same game modes with AI-controlled bots; and a Weapons Course, a single player map serving as a tutorial and a training mode. Online play Global Offensive supports matchmaking and leaderboards for all online game modes, provided by Steam. The provided online service offers the ability to filter by game modes, maps and a built-in Steam friend system. Valve also employs Valve Anti-Cheat, which can automatically remove and ban players from the Valve online network. To match players of similar skill levels for an enjoyable experience, the game uses a heavily modified version of Elo rating system. The PC version of Global Offensive also supports private dedicated servers that the player may connect to through the community server menu in-game. These servers may be heavily modified and can be completely different from the base game. Development Global Offensive began as a port of Counter-Strike: Source to Xbox Live Arcade by Hidden Path Entertainment. During the development Valve saw the opportunity to turn the port into a full game and expand on Counter-Strike‍ '​s gameplay. Global Offensive began development in March 2010 and was revealed to the public on August 12, 2011. The closed beta started on November 30, 2011, and was initially restricted to around ten thousand people who received a key at events Valve attended to showcase Global Offensive. After issues such as client and server stability were addressed the beta was opened up to progressively more and more people (approximately 100,000 beta keys were given out as of July 4, 2012), until the beta became open for anybody to join and play.[25] Before the public beta Valve invited professional Counter-Strike and Counter-Strike: Source players to play-test the game and give feedback. At E3 2012, Valve announced that Global Offensive would be released August 21, 2012 on all platforms, with an open beta starting roughly a month before that. It was never released on the PlayStation Network in Europe. Post-release Global Offensive initially launched with four game modes: Classic Casual, Competitive, Demolition, and Arms Race, and several official maps for each of the game modes. The Deathmatch game mode as well as more official maps, some user-made, were added post-release. The mechanics for the Hostage Scenario were revamped post-release. New weapons, such as the CZ-75 Auto, were added post release. The statistics for the weapons and the layout of the maps were modified post-release for competitive balance. Cosmetic items, such as weapon finishes, were added on August 13, 2013 in a major update named the "Arms Deal" update. Most cosmetic items are received via game-end drops and opening virtual crates with keys that can be bought through microtransactions, similar to the item drop systems in Team Fortress 2 and Dota 2. These items can also be traded between players through the Steam trading system or the Steam Community Market. Valve enabled Steam Workshop support for Global Offensive, allowing users to upload user-created content, such as maps, weapon finishes, and custom gameplay scenarios, and subscribe to user-uploaded maps to download them. In previous versions of Counter-Strike, players had to download maps through third party sites or while attempting to connect to a server. The Steam Workshop is controlled by Valve, and they reserve the right to remove content. Valve supported community map-makers in the form of "operations", which act like expansion packs and require players purchase "operation passes" to play community made maps on Valve's official servers (this does not affect the map being played on community servers), with the exception of Operation Breakout which doesn't require the player to buy a pass. Each operation only lasts a certain amount of time before a new operation is released, requiring players to buy a new pass. A portion of the income generated through pass sales is given to the creators of the maps. Popular user-created weapon finishes will have the chance to be added in the game as official cosmetic items in updates, where they can be received in virtual crates. A portion of the income generated through the sale of keys in order to receive these finishes is given to the creators of the weapon finishes.