The game is played from a third-person perspective and its world is navigated on-foot or by vehicle. Throughout the single-player mode, players play as Niko Bellic. An online multiplayer mode is included with the game, allowing up to 32 players to engage in both co-operative and competitive gameplay in a recreation of the single-player setting.[b] Two expansion packs were later released for the game, The Lost and Damned and The Ballad of Gay Tony, which both feature new plots that are interconnected with the main Grand Theft Auto IV storyline, and follow new protagonists.
Development began soon after the release of Grand Theft Auto: San Andreas and was shared between many of Rockstar's studios worldwide. The game introduced a shift to a more realistic and detailed style and tone for the series. Unlike previous entries, Grand Theft Auto IV had no strong cinematic influence, as the team attempted an original approach to the story. As part of their research for the open world, the developers conducted field research around New York throughout development and captured footage for the design team.
Following its announcement in May 2006, Grand Theft Auto IV was widely anticipated. Upon release, the game received universal critical acclaim, with praise particularly directed at the game's narrative and open world design. However, the game also generated controversy, with criticism directed at the game's depiction of violence and players' ability to drive under the influence of alcohol. Grand Theft Auto IV broke industry sales records and became the fastest-selling entertainment product in history at the time, earning US $310 million in its first day and US $500 million in its first week. Considered one of the most significant titles of the seventh generation of video games, and by many critics as one of the greatest video games of all time, it won year-end accolades, including Game of the Year awards from several gaming publications. A sequel, Grand Theft Auto V, was released in September 2013.
Grand Theft Auto IV is an action-adventure game played from a third-person perspective. Players complete missions—linear scenarios with set objectives—to progress through the story. It is possible to have several active missions running at one time, as some missions require players to wait for further instructions or events. Outside of missions, players can freely roam the game's open world, and have the ability to complete optional side missions. Composed of the fictional city of Liberty City, the world of Grand Theft Auto IV is larger in area than most earlier entries in the series. At the beginning of the game, players can only explore the first island–composed of Dukes and Broker–with all other islands unlocking as the story progresses.
Players use melee attacks, firearms and explosives to fight enemies, and may run, jump, swim or use vehicles to navigate the game's world. There is a first-person perspective option when using vehicles. In combat, auto-aim and a cover system can be used as assistance against enemies. Should players take damage, their health meter can be fully regenerated using multiple techniques, such as eating, using medical kits, or calling for paramedics. If players commit crimes while playing, the game's law enforcement agencies may respond as indicated by a "wanted" meter in the head-up display (HUD). On the meter, the displayed stars indicate the current wanted level (for example, at the maximum six-star level, efforts by law enforcement to incapacitate players become very aggressive). Law enforcement officers will search for players who leave the wanted vicinity. The wanted meter enters a cooldown mode and eventually recedes when players are hidden from the officers' line of sight.
The game's cover system allows players to move between cover, to fire blindly, aim freely, and target a specific enemy. Individual body parts can also be targeted. Melee attacks include additional moves, such as dodging, blocking, disarming an opponent and counter-attacking. Body armour can be used to absorb gunshots and explosive damage, but is used up in the process. When health is entirely depleted, gameplay stops, and players respawn at the nearest hospital.
The game's single-player mode lets players control a war veteran, Eastern European Niko Bellic. During the story, Niko meets various new characters, many of whom he befriends. These characters can then perform favours for Niko whenever he asks; for example, his cousin Roman, who owns a taxi service, can send one of his cabs to Niko and take him to any destination around the city. Cabs are always available during gameplay, allowing players to quickly travel to a destination. Throughout the course of the game, players are also faced with morality choices, which alter the storyline appropriately depending on the player's choice. While free roaming the game world, players may engage in context-specific activities such as bowling or darts. Other available activities include a vigilante minigame, and in-game television programming. Niko has a smartphone for contacting friends and starting activities. The smartphone is also used to access the game's online multiplayer mode, and to enter cheat codes. To access the in-game Internet, which allows Niko to send and receive emails and set up prospective dates with potential girlfriends, Niko can use Internet cafés located around the city.The game also features a subway system, allowing players to quickly traverse through the game world.
The online multiplayer mode for Grand Theft Auto IV allows up to 32 players to freely roam across a recreation of the single-player world.[b] Players decide which game mode that they wish to play, including deathmatches and street races. Both cooperative and competitive game modes are available. These game modes are split into ranked and unranked matches. For players to level up through ranks, in-game money must be earned. The game also features a Free Mode, in which players have the entire map open to explore, with no end goal or mission to complete. Hosts of the game can control many variables, such as police presence, traffic, and weapons. LAN support is available in the Windows version of the game.