Counter-Strike: Global Offensive is a modern military first-person shooter developed by Valve (in conjunction with Hidden Path) and published by Valve for the PC (via Steam), Mac (also via Steam), Xbox 360 (via Xbox Live Arcade), and PlayStation 3 (via PlayStation Network) on August 21, 2012. The fourth official iteration of Counter-Strike (and the second one based on the Source engine), Counter-Strike: Global Offensive (or CSGO) features new maps (including updated versions of nine of the maps from the original Counter-Strike), new weapons (including a molotov cocktail and a stun gun), new game modes (including an official variation of the Gun Game mode), and ranked matchmaking (using the Elo rating system).
The game also includes numerous minor gameplay enhancements, including weapon price rebalancing, enhanced bot interaction (allowing bots to take place of empty player slots and allowing dead players to take full control of alive bot teammates), map-based player models (removing the ability to select one manually), and a weapon training mode.
Since November 30, 2011, Valve has released the game in closed beta form to certain players (which significantly increased as time progressed). From August 14th, 2012 to the game's release date, Valve re-opened the beta to those who pre-ordered the game since August 7th. Along with purchasing it at a 10% discount, the pre-order also includes an item for Team Fortress 2 (the "AWPer Hand", a re-skin of the Sniper's sniper rifle featuring the sounds and likeness of the AWP rifle from Counter-Strike: Global Offensive).
Two of the standard game modes from previous Counter-Strike games (Bomb Defusal and Hostage Rescue), make a return in the "Classic" game mode, which comes in two forms: Classic Casual and Classic Competitive.
Classic Competitive plays more like the traditional Counter-Strike games while Classic Casual disables friendly fire, team collision, and purchasing requirements of armor (everybody has one automatically) and defusal kits (all Counter-Terrorist players have them automatically), while increasing the cash reward after each kill (but decreasing the maximum cash cap from $16000 to $10000). The team with the most amount of wins out of 30 (10 for Casual on consoles, 15 for Casual on PC) rounds wins the match.
Nine maps from the Counter-Strike franchise make a return just for Classic mode (with a "SE" variant that removes fog, props, and certain visual effects for professional play), although custom servers can permit these maps to be played in other game modes).
In Bomb Defusal, the Terrorist players must plant a C4 Explosive (randomly given to one player) in one of the two designated "bomb sites" and prevent the Counter-Terrorist players from defusing it before it detonates. While players cannot move or attack while planting or defusing, they can prematurely stop and restart the process. It takes half a minute for armed explosives to detonate (the round time stops and the music and bomb sound effects change at key points prior to detonation) and ten seconds to defuse the explosive (which can be halved if the player is carrying a Defusal Kit).
Terrorist players win by either detonating the explosive or eliminating the Counter-Terrorist players. Counter-Terrorist players win by either defusing an armed explosive, letting the round time expire, or eliminating the Terrorist players prior to them arming the explosive.
In Hostage Rescue, the Counter-Terrorist players must rescue hostages kept near the Terrorist spawn and escort them to a designated "rescue zone" located near their spawn. Each hostage stands in one spot and must be "interacted" (using the Use button) by a Counter-Terrorist player, in which he will follow the player until either he reaches the rescue zone, he get "interacted" again by the same player (in which he "waits"), the Counter-Terrorist player dies, or he dies. Any player (on either team) who harms a hostage suffers a cash penalty, and any player who kills a hostage suffers a greater cash penalty (and the risk of being slayed, kicked, or banned from the current server).
Counter-Terrorist players win by either recusing at least half of the total number of hostages or eliminating the Terrorist players. Terrorist players win by either letting the round time expire or eliminating the Counter-Terrorist players.
A fast-paced variation of the Bomb Defusal game mode, Demolition disables the ability to buy weapons and gear. Instead, the player's starting weapon is based on both their weapon difficulty and their amount of kills in the previous round. While team collision is disabled, friendly fire is enabled. The team with the most amount of wins out of 20 rounds wins the match.
During each round, if a player gets one kill (with any weapon or equipment), then he/she gains a weapon difficulty level (up to the maximum level) for the next round. If a player gets more than one kill, then along with the weapon level gain, he/she gets one grenade (HE Grenade for two kills overall, Flashbang for three kills, or Incendiary Grenade for four kills) for the next round.
There are six new medium-sized maps developed just for this game mode (although custom servers can permit these maps to be played in other game modes). Other than their size, a key difference from other Bomb Defusal maps is that these maps only have one "bomb site" located near the center of the map.
The game's official variation of Gun Game, Arms Race is a team deathmatch mode where individual players compete to win the match by being the first player to score a kill with a Gold Knife. Players must earn their Gold Knives by killing enemy players with all of their designated weapons consecutively. While team collision is disabled, friendly fire is enabled. Players have infinite ammo and instantly respawn after their killcam, in which they are invulnerable for a few seconds (or until they fire their weapon). Each match has only one round.
Each player starts at the first weapon rank, equipped with a MP9 and a knife. Killing a player with their equipped gun increases that rank and immediately switches it with the weapon of the next rank. Killing a player with a standard knife increases the killer's weapon rank while decreases the victim's weapon rank. Committing suicide causes the player to decrease their weapon rank.
There are three new small maps developed just for this game mode, each just containing the designated spawn zones for each team.
Counter-Strike: Global Offensive includes 29 lethal guns to choose from, split up into five categories: Pistols, Submachine Guns, Rifles (both Assault Rifles and Sniper Rifles), and Heavy Weapons (both Shotguns and Machine Guns). The game also has six types of grenades (and a single-use taser), each varying in utility. Players can equip only one primary weapon (Submachine Guns, Rifles, and Heavy Weapons) and one secondary weapon (Pistols) at a time. They may also carry up to three grenades at a time (each of which must be unique) and one taser at a time.
In Classic game modes, most of the weapons and equipment must be bought using the game's currency (gained by completing matches, winning matches, performing objectives, and getting kills).