Silencer

The Suppressor (or Silencer in some games) is a weapon attachment available in Call of Duty: United Offensive, Call of Duty 4: Modern Warfare, Call of Duty: World at War, Call of Duty: Modern Warfare 2, Call of Duty: Black Ops and Call of Duty: Modern Warfare 3. This attachment prevents gunfire from showing up on enemy minimaps and makes it harder to hear and locate the position of the shooter. It also somewhat reduces the muzzle flash of the weapon. As a disadvantage, the suppressor either reduces the range at which weapons do their maximum damage, reduces damage of the weapon as a whole, or decreases the damage done by the weapon at its longest range depending on what weapon the suppressor is used with.

Call of Duty: United Offensive
The first use of suppressors in the Call of Duty franchise were in the Sicily levels of Call of Duty: United Offensive. A suppressed Sten was the only default weapon Sgt. Doyle started with. He can acquire weapons from dead German soldiers but the suppressed Sten is given so the player can get up to the fortifications without alerting any enemies present. Ironically, all fire from the German weapons do not alert any of the enemies, even though these arms do not use suppressors.

If the player ends the first Sicily level with the suppressed Sten, it returns for the next level. However, it is impossible to complete the mission with only the suppressed Sten as the player cannot use the ammo from the MP40s, even though it is the same type. However, it can be kept as a secondary weapon, using any captured German gun as a primary.

Call of Duty 4: Modern Warfare
"Invisible on GPS when firing, reduced muzzle flash, but shorter range."

- Attachment description

Singleplayer
Suppressors are attached to the USP .45 in All Ghillied Up, One Shot, One Kill, Ultimatum, All In, No Fighting In The War Room, and Mile High Club, the MP5 in Crew Expendable, Ultimatum and Mile High Club, the M4A1 SOPMOD in a majority of MacTavish's missions, the M21 in Blackout and All Ghillied Up, and the P90 in All Ghillied Up. In stealth-based missions, such as All Ghillied Up and the start of Blackout, the silencer is necessary in order to kill with the player's gun. If using an unsilenced weapon, the enemies will be alerted, and at most, can lead to the player's failure of the mission.

Multiplayer
Suppressors can be used on all pistols except the Desert Eagle, assault rifles, and submachine guns. When a player fires a weapon without a suppressor, they will temporarily appear as a red dot on the mini map to enemy players. Firing a suppressed weapon will not cause the player to appear on the mini map in this fashion. The suppressor also reduces shot volume and muzzle flash. Note that a suppressed weapon grants no amnesty from the UAV Recon.

The "invisibility" afforded by the mini-map is invaluable for flanking or ambushing. Even when enemies are alerted to the player's presence, they must either call a UAV or make a visual in order to locate the player. Along with the reduced shot loudness, this makes it much more difficult to locate, and furthermore track, the player's movements.

The major disadvantage of the suppressor is the reduction in damage over range. Damage over range is reduced to about 70% of its original value for submachine guns and pistols, and to less than 50% for assault rifles. It should be noted that at a 25m range and beyond, bullets from a suppressed assault rifle will be dealing their minimum damage, while an unsuppressed assault rifle will still be dealing maximum bullet damage. This emphasizes the use of suppressors as a close to mid-range attachment.

Despite the range penalty, powerful and loud weapons such as the AK-47 or the M14 can become somewhat more manageable with a suppressor in certain situations. Such weapons are often plagued with being a combat magnet from the range at which they can be heard firing. With a suppressor, they become particularly devastating at mid range due to the stealth and sheer power.

As the only thing which can reveal a player on the radar while using suppressed weapons is a UAV, the UAV Jammer Perk is an obvious choice for those wishing to take the pure stealth option. A suppressor + UAV Jammer class can easily cause chaos in the rear lines of the enemy ranks. Attaching a suppressor without the UAV Jammer is more risky than choosing a UAV Jammer without a suppressor, as if an enemy player acquires UAV Recon, the player using the suppressor will suddenly be revealed, taking the stealth effect provided by the suppressor away. Therefore, on larger matches, it's preferable to either take both or just the UAV Jammer, as a well-timed ambush can kill many enemies in a short space of time, negating the need for a suppressor as the impending threat of the enemies is removed. As an alternative, a suppressed pistol can be used, acquiring kills without alerting the enemy team of the user's location.

Flanking the enemy may also be an effective technique, achieved by use of Extreme Conditioning. Dead Silence may also be an effective choice, particularly in Search and Destroy, where players often tend to listen carefully for enemy footsteps.

The suppressor attachment is unlocked at 75 kills (Marksman II) for submachine guns and assault rifles. The attachment is automatically unlocked for pistols when the pistol itself is unlocked, excluding the Desert Eagle, which cannot accept a suppressor.

Call of Duty: World at War
Working in the same fashion as their Call of Duty 4: Modern Warfare counterparts, the Gewehr 43 and all submachine guns except the PPSh-41 can have suppressor attachments to them. Oddly, the Gewehr 43 with the suppressor attachment will have the same reload animation for mid-magazine reloading as empty magazine reloading, similar to the M14 when equipped with an M203 in Call of Duty 4. The reload at partial magazine is hastened so that it takes the same amount of time as a normal mid-mag reload, but if the entire magazine is spent it will reload as slow as it normally would. Enemies will have difficultly finding the player's exact position if he catches him off guard. Missed shots are also less detrimental with the suppressor, as the enemy will have more difficulty telling where the shots came from, however they will still hear the crack of the bullets flying past them and see the tracer shots.

Unlike Call of Duty 4: Modern Warfare, pistols do not have suppressors and they cannot be unlocked.

Weapon Compatibility

 * Gewehr 43
 * Thompson
 * MP40
 * Type 100

Call of Duty: Modern Warfare 2
Suppressors return in Call of Duty: Modern Warfare 2 as an attachment for Submachine Guns, Handguns, Assault Rifles, Shotguns, Sniper Rifles, Light Machine Guns, and Machine Pistols. Only launchers, the Riot Shield, high caliber pistols (.44 Magnum and Desert Eagle) and Akimbo-capable Shotguns (Ranger and Model 1887) cannot accept suppressors.

SMGs, Pistols, and Machine Pistols suffer the least from equipping a suppressor, as there is only a slight reduction in range with no reduction in base damage. Assault rifles suffer a considerable range reduction, but do not suffer a reduction in base damage. Suppressors reduce Sniper Rifle base damage values from 70 to 50. Without Stopping Power, it will always require at least two shots to kill an enemy with any suppressed sniper rifle. Suppressors also reduce base damage values by 10 points on Light Machine Guns. Shotguns suffer an extreme reduction in range when using suppressors, and are considered unusable by most players. The one exception to this is the Striker, which suffers much less of a range reduction than other shotguns when equipped with a suppressor. When combined with the perks Cold-Blooded and the pro version of Ninja, the suppressor makes a player completely invisible to all forms of detection other than being seen or making noise by doing things like falling, switching weapons, defusing a bomb, activating a killstreak, or shooting, although shooting is obviously much less noticeable when using a suppressor. Special consideration should be given to Killcam when operating such a class; precautions such staying in ADS for a few seconds after a kill can be essential in disguising the player's position. Strangely, all of the weapons seem to use the same suppressor model.

Suppressor-Radar glitch
Because of a glitch, using a suppressor on these weapons in any version of Call of Duty: Modern Warfare 2 does not prevent the shooter from showing up on enemy radar:
 * M240
 * M9
 * MG4

Campaign
The suppressor appears on the AUG and the M1911 (if switched, before being replaced by the Crossbow later on) in the mission WMD. It also appears on a FAL and a Skorpion in the mission Operation 40, as well as being used by Carlos on his M16 when on the plane.

Multiplayer
The suppressor is worth in Create-A-Class. As in Modern Warfare 2, the Suppressor affects the range of weapons with this attachment rather than the damage, except for the SPAS-12, which has no downsides to having a Suppressor attached as its range and damage is not reduced. In addition, sniper rifles get their damage reduced. The sounds made while firing are the same for most suppressed guns. However, the Commando, Galil, AK-47, FN FAL, M14 and M16 do have a unique firing sound when suppressed.

Following the title update for Black Ops, damage multipliers were increased for headshots on all sniper rifles that have an attached suppressor, making one shot kill headshots possible in all Core playlists. Before the 1.06 patch, however, players using Warlord as their Tier 2 perk and attached both a Suppressor and another attachment, the headshot multipliers did not take effect.

Call of Duty: Black Ops (Nintendo DS)
Suppressors are first seen on two weapons, the M40A1 and the Hush Puppy, though it is also available for the Dragunov, the PPSh-41, the Makarov PM and the M10. It will prevent enemies from reacting to the player's shots, and keeps the player off the radar in multiplayer when shooting.

Call of Duty: Modern Warfare 3
The suppressor was first spotted in the first reveal trailer being sported by several MP5 submachine guns. It was also seen in use on some AK-47s, with or without the ACOG scope or Grenade Launcher. It behaves similarly to the previous variants, making the player not appear in the mini-map when firing, as well as dampening the muzzle flash and sound, but reducing the effective range of the weapon.

In multiplayer it can be used on nearly all the weapons with exceptions being Launchers and certain pistols. It is unlocked at Weapon Proficiency Level 2 for Pistols and Machine Pistols, and Weapon Proficiency Level 5 for every other weapon.

Trivia

 * Much like the Grenade launcher, ACOG scope, and Red Dot Sight attachments, the suppressor model in Black Ops varies depending on the origin of the weapon.
 * In the Wii version of Call of Duty: Black Ops, the Enfield, Galil, AK47, and Commando have their RPM reduced from 750 RPM to 630 RPM when equipped with a suppressor.
 * The silencer is the only attachment that can be seen in 3rd person in the Wii version of Black Ops.