FlaK 88

The  is a German anti-aircraft/anti-tank artillery gun featured in all WWII Call of Duty games, and typically used as either mission objectives to plant explosives on, or more rarely controlled by the player. FlaK is a contraction of Flugzeugabwehr-Kanone meaning "anti-aircraft gun" (hence the final K being capitalised), and the name is a nickname; commonly just called the 88 regardless of version.

Campaign
In Call of Duty, these weapons can be used by the player during the missions "Pegasus Bridge", "Pegasus Bridge-Day", "Festung Recogne" and "V-2 Rocket Site". The 88's primary use in these missions are destroying attacking German tanks. It has infinite ammunition and is primarily limited by a slow reload and traverse speed. The weapon has no ADS mode, and is aimed using the same black T-shaped crosshair as the Flakvierling.

In other missions, the player is assigned to destroy FlaKs; this is done in "Brecourt", at the base of "The Eder Dam" and in "Berlin". Typically this is performed by planting timed explosives on them. They also appear as objectives during the second tank level in the Russian campaign, "Oder River Town"; here, they can be destroyed by simply firing at them with the T-34's main gun.

Multiplayer
FlaK guns are usable in Call of Duty: United Offensive  multiplayer. They are very powerful anti-tank weapons, capable of destroying tanks with at most two shots and tank destroyers with at most three. They are invulnerable, making them very useful. However, the player can still be killed while using one, so it should be used with caution.

Call of Duty 2
In Call of Duty 2, the FlaK 88 has regressed back to its role as a mission target. They can be used at many different times, but they're only required in "Hold The Line". Call of Duty 2 uses the same white crosshair for them as is used for other fixed weapons.

Call of Duty 2: Big Red One
In Call of Duty 2: Big Red One, the player takes control of a FlaK 88 in order to destroy enemy bunkers in "The Great Crusade". It is the only time a FlaK 88 is used in Call of Duty: Big Red One. The player can use an over the top first-person view on the gun and can still take damage while using the FlaK 88.

Call of Duty 3
In Call of Duty 3, the player is tasked with destroying FlaK 88's in the levels "Night Drop" and "Laison River". They may have to destroy them by taking out their crews or by placing explosive charges on them.

Call of Duty: Roads to Victory
The destruction of FlaK 88s, or "88s" as they are known in-game, is the objective of many missions in Call of Duty: Roads to Victory. In Hunner Park, just before Gerald Miller destroys one FlaK 88, his officer stops him, allowing him to instead use it to defend against enemy tanks and half-tracks.

Call of Duty: World at War
In Call of Duty: World at War  FlaK 88s are featured in the levels "Vendetta," "Blood and Iron" and "Heart of the Reich." They are featured as enemies during the tank-driving mission "Blood and Iron" and explosives must be planted on several guns during "Heart of the Reich." The FlaK 88s are unusable by the player. At this point, the player gets checkpoints by destroying the first two, then the last two.

Call of Duty: World at War (Nintendo DS)
The FlaK 88 is found in the American Campaign used by the Japanese, even though it looks exactly the same as the FlaK 88 from the console games. These are only used by Rook to stop ammo boats.

Trivia

 * The original game's FlaK model has the tapered one-piece barrel of a FlaK 18, while the second game's has the two-piece barrel of a 36.
 * The T-55 reuses the Call of Duty 2: Big Red One FlaK 88's firing sound.