Lightweight

Lightweight is a Tier 2 perk featured in Call of Duty: Modern Warfare 2 and a Tier 1 perk featured in Call of Duty: Black Ops.

Call of Duty: Modern Warfare 2

File:Light.png

The Lightweight perk icon.

File:LightPro.png

The Pro version of Lightweight.

In Modern Warfare 2, it allows players to move faster. It is available at the start of the multiplayer game, in the First Recon default class, and at level 4 when Create-A-Class is unlocked it is also immediately available.

The perk currently allows players a 7% movement speed increase, following a discovery that the PC Patch 1.06 decreased it from its original 10% speed boost. When upgraded to Pro, after sprinting 30 miles with the perk equipped, users are able to fire their weapons faster after sprinting. It cuts the time between sprinting and firing in half, similar to how Sleight of Hand halves the time taken to aim down the sight. The description, however, on the multiplayer screen states it provides "Faster ADS after sprinting", which is misleading to some players.

Sprinting 250 miles with Lightweight activated completes the Lightweight Pro VI challenge, and unlocks the Perk picture as an Emblem and also gives the Title "Pathfinder".

Call of Duty: Black Ops

Lightweight returns as a Tier 1 perk in Black Ops. Its effect is unchanged in that it still increases the user's movement speed, but by how much is currently unknown.

Lightweight:

Move faster

Lightweight Pro:

? (Classified)

The pro version of Lightweight is unlocked by completing three challenges.

Escape Death: Escape death 5 times after being shot.
Melee: Unknown. Presumably for getting melee kills with Lightweight.
Offense Medal: Unknown.

Tips

The perk is most effective with use of Marathon as a tier 1 perk, as both greatly upgrade the user's sprinting abilities. It can be used with a Rushing class, especially with Commando or Ninja as a tier 3 perk; Commando's pro version lets players receive no falling damage, so using this with a rushing class, especially on maps such as Quarry where there are several fatal drops is very useful. Ninja is also one of the preferred tier 3 perks as it offers silence with its pro version.
A common tactic is also using Commando and Marathon in conjunction with Lightweight, is to create a Melee Specific custom class, and sprint across maps only knifing people, as Commando greatly increases the knife range, and Marathon and Lightweight are both effective in allowing players to do so with ease. This tactic is generally frowned upon, as due to lag, it can cause players to appear to "teleport" through bullets.
A less frowned upon tactic is to couple Lightweight with a CQC weapon, such as a shotgun or SMG for a "run and gun" custom class. This also takes fuller advantage of Lightweight Pro's capabilities than a melee class, since Pro allows a sprinter to fire their weapon in half the time it would otherwise take. A player who only knifes will not reap any benefit from this Pro ability, and it is therefore wasted on them.
The perk is also very useful in objective gamemodes where capturing points is needed, for example Domination or Capture the Flag. Again, Marathon is very helpful.
Lightweight Pro, coupled with Sleight of Hand Pro, is incredibly useful in Hardcore, as both offer traits which allow the user to ADS faster than usual. Because there are no hipfire crosshairs, aiming down the sight is often needed in Hardcore to accurately hit targets, and using Lightweight Pro will outgun any other sprinting player in close quarters. Sleight of Hand Pro adds to this as it allows faster ADS.
Because this perk's challenges require such long distance requirements, it is very useful to use Marathon with this perk to upgrade to the Pro version as it will allow the player to sprint for much longer per game.
This perk, coupled with a high-mobility weapon, is required to reach some difficult jumps in multiplayer.
There was a glitch that allowed the Pro Perk VI challenge to be completed in approximately 6 minutes. To do this, the player had to perform the "elevator" glitch on Karachi, run to the end of the map, and continue to sprint at the escalated miles per hour. This has since been patched with the Stimulus Package update for Xbox 360.

Trivia

Modern Warfare 2

This perk was seen in the teaser trailer in early 2009 on the sign hanging over the security checkpoint.
The icon for this perk is the winged shoe of the Greek God Hermes.