Call of Duty: Black Ops/Gameplay

Black Ops is a first-person shooter. The player assumes the role of a foot soldier who can wield various firearms, of which two at a time can be carried; throw grenades and other explosives; and use other equipment as weapons. A player close enough to an enemy can kill with one knife blow. A character can take three stances: standing, crouching, or prone; each affects rate of movement, accuracy, and stealth. The player can dive prone from a standing position when running. The player can momentarily sprint but will then grow tired. The screen glows red to indicate damage to a player's health, which goes away over time. When the character is within the blast radius of a live grenade, a marker indicates the direction of the grenade, helping the player to flee or throw it back. Among the game's weapons are crossbows with bolts and explosive ammunition, Dragon's Breath rounds and ballistic knives.

Campaign
The player assumes the role of various characters during the single-player campaign, changing perspectives throughout the story. The playable characters are special forces operatives conducting black operations behind enemy lines. In this way, the player's characters have their own traits such as voices and shadows. Each mission features a series of objectives that are displayed on the heads-up display, which marks the direction and distance towards and from such objectives. The player is accompanied by friendly troops throughout the game. Although primarily a first-person shooter, the player pilots a Hind helicopter and guides friendly troops from a SR-71 Blackbird reconnaissance aircraft. The campaign features several scripted cinematic moments. One of them is a bullet time effect during the "Victor Charlie" level, activated when the player fires toward the last enemy of a Viet Cong squad.

Multiplayer
The online multiplayer mode of Black Ops retains the experience points and unlockable reward system that has been kept since Call of Duty 4. The game's multiplayer focuses on socialization and customization. "Create-a-Class 2.0" allows enhanced personalization with appearance items as well as upgradable perks; weapons are extensively customizable with writing, emblems, attachments and camouflage painting. Even reticles can be modified. There are more than one style for an attachment, which allows for a lot more personalized weaponry; for example, the player can choose between a red dot sight or a reflex sight, both of which share many of the same traits, although the red dot fills up less of the screen (something desired by many players). Character models depend on the first tier perk instead of the weapon's type. Furthermore, face paints can be unlocked. New custom killstreak rewards include explosive R/C cars, guided missiles and controllable attack helicopters.

A currency system has been implemented allowing players to buy weapons, accessories and clothes. Players can gamble with their "COD Points" in a free-for-all based playlist called "Wager Match", which is composed of four game modes. Time limited objectives known as "Contracts" can be purchased to gain more currency and experience points. The progression system is not featured in local split-screen multiplayer. In local split-screen play, all character customization options are already unlocked. Players can no longer define game rules such as win conditions.

Players can play alone or with friends against AI opponents in "Combat Training" with a separate progression system. Online split-screen is re-introduced on Xbox 360 and PS3. The guest account can rank up but is reset after each sign out. Only on Xbox 360, a second Gold Xbox Live account can be used to keep the second player's progression.

For the first time in the series, clips from online gameplay can be recorded. Some specific features that have been removed from the PC version of Infinity Ward's Modern Warfare 2 return, such as lean, mod tools, the developer console and dedicated servers. Dedicated servers are exclusively provided by Game Servers. Steam is the exclusive platform for Black Ops on PC, and the game is protected by Valve Anti-Cheat.

The Wii version of the game includes in-game voice chat. This is the first Call of Duty title to include the voice chat feature for the Wii. Nintendo and PDP have partnered to release the first headset to be used with the Wii known as PDP's Headbanger Headset.

Zombies
A zombie cooperation mode, titled "Zombies", is included in the game. Originally being featured in World at War, it was revamped to be included into Black Ops. It is a four-player online and two-player split screen co-op mode (which can also be unlocked online). In the map "Five", players take the roles of John F. Kennedy, Richard Nixon, Robert McNamara, and Fidel Castro as they fight zombies at The Pentagon. There is one map based on the original game called Kino Der Toten ('Theatre of the Dead' in German). This map features the characters from World at War -- Edward Richtofen, Tank Dempsey, Takeo Masaki, and Nikolai Belinski. Limited editions of the game offers four zombie maps from World at War. There is also an unlockable top-down two-stick arcade-shooter version of Zombies known as Dead Ops Arcade.