Call of Duty 4: Modern Warfare is a first-person shooter video game developed by Infinity Ward and published by Activision for Xbox 360, PlayStation 3, and Windows. It is scheduled for release for Mac OS X in May 2008. It is the fourth installment of the Call of Duty video game series, excluding expansion packs. The game breaks away from the World War II setting of previous games in the series and is instead set in modern times. The game is the first in the series to be rated Mature in North America. The title and game details were announced on April 25, 2007, and the game was released worldwide between November 6, 2007 and November 9, 2007. It became available on Steam on November 6, 2007 for pre-purchase, and was available to play on November 12, 2007.

The story is centered around a fictional near-future conflict involving the United States, the United Kingdom, and Russia, who are fighting against Russian ultranationalists in civil war torn Russia, and rebels that have staged a coup d’état in a small Middle Eastern country. It is told from the perspectives of a United States Marine and a member of the British SAS, and is set in multiple locations, including the Middle East, Azerbaijan, Russia, and Prypiat, Ukraine. The multiplayer portion of the game features various game modes, and contains a leveling system that allows the player to unlock additional weapons, weapon attachments, and camouflage schemes as they advance. The game was in development for two years. It uses a proprietary game engine, and includes features that include true world-dynamic lightning, HDR lighting effects, dynamics shadows, and depth of field.

Call of Duty 4: Modern Warfare received considerable praise and has won numerous awards from gaming websites, including IGN’s "Best Xbox 360 Game". It was the top-selling game worldwide for 2007, reaching over than seven million copies as of January 2008.

Gameplay

Call of Duty 4: Modern Warfare is a first-person shooter similar to previous games in the Call of Duty series, but set in the present-day instead of World War II.

The game’s move to modern warfare introduces new weapons and technology to the Call of Duty franchise, including the M203 grenade launcher, M4A1 carbine, the AN/PEQ-2 Target Pointer for use in conjunction with night vision goggles, the MP5SD submachine gun, and the FGM-148 Javelin portable anti-tank guided missile.[9] The player gains access to these over the course of the game, but may only carry up to two weapons in addition to grenades. Weapons from fallen foes can be picked up to replace weapons in a player’s arsenal. Players also have additional abilities, including a grenade launcher attachment, night-vision googles, and the ability to call in airstrikes.

The gameplay of Call of Duty 4 shares several features with previous iterations of the franchise. Once again, players fight alongside AI-controlled teammates. They help during the game’s missions by providing cover fire, shooting down enemies, and clearing rooms for entry.

A character can be positioned in one of three stances: standing, kneeling, or prone; each affecting the character’s rate of movement, accuracy, and stealth. Using cover helps the player avoid enemy fire or recover health after taking significant damage, as there is no armor or health powerups. When the character has taken damage, the edges of the screen glow red and the character’s heartbeat increases. If the character stays out of fire, the character can recover. When the character is within the blast radius of a live grenade, a marker indicates the direction of the grenade, helping the player to either flee or toss it back to the enemy.

Campaign

Similar to previous games in the series, the player takes on the role of various characters during a single-player campaign. The characters’ involvement in the plot occurs simultaneously and overlaps the events in the game. As such, the player’s perspective can change from one character to another between missions.

Each mission features a series of objectives; the player is led to each objective with the head-up display, which marks its direction and distance. Some objectives require that the player arrives at a checkpoint, while other objectives require the player to eliminate enemies in a specified location, stand their ground to defend an objective, or plant explosive charges on an enemy installation. The player is often accompanied by friendly troops, who cannot issue orders. Laptop computers containing enemy intelligence appear throughout the campaign, and can be collected to unlock game bonuses.

After completing the campaign, a special epilogue mission is unlocked for play. The mission itself has no bearing on the campaign plot, and focuses on an SAS squad fighting terrorists that have hijacked an airplane and taken a VIP hostage.

Campaign

Call of Duty 4 features team-based and deathmatch-based multiplayer modes on various maps. Each mode has an objective that requires unique strategies to complete. Players can call in UAV reconnaissance scans, air strikes, and attack helicopters, when they achieve three-, five-, and seven-enemy kill streaks respectively. A game ends when either a team has reached a predefined number of points, or the alloted time expires in which case the team with the most points wins. However in the rare case the points are even when the time expires, Sudden Death mode is activated in which there is no re-spawning and the team who either has the last man standing, or achieves the objective first are the winners.

The player’s performance in the multiplayer mode is tracked with experience points, earned by taking down other players, completing objectives, or by being a member of a winning team. As the player gains experience, they advance in level, unlocking new weapons, perks, challenges, and gameplay modes. The highest obtainable level is 55, but on the console versions of the game, the player has the option to play "Prestige" mode; this resets their level back to 1 and all earned bonuses are lost in exchange for a special in-game insignia. This process can be repeated up to 10 times with a different insignia being given each time, giving the player a total of 605 levels to achieve. Leaderboard statistics, including kills, deaths, and playing time, are not affected by Prestige mode.

Completing a challenge grants experience points and may unlock weapon attachments. When a player’s level increases, it may unlock new weapons, perks, or challenges. At lower experience levels, the player only has access to five pre-determined classes, and cannot create a custom class with the weapon of their choosing. However, as the player advances in levels, they earn the ability to customize their classes. This includes selecting their main weapon, side arm, and special grenade type. Additionally, the player can select a limited number of "perks" that can customize their character further. Perk effects include increasing damage by the player, being able to take more damage, or detonating a grenade after being killed in an act of martyrdom. The player is also given challenges to attempt, including achieving a certain number of kills with a specific weapon or shooting down a helicopter or performing a number of head shots.