Frag x3

Frag x3 is a Tier 1 perk in Call of Duty 4: Modern Warfare that gives a player three frag grenades upon spawning rather than the regular one. However, if playing in Old School mode it is possible to get up to four. It is unlocked for use at level 41.

Overview
This perk is a commonly used first-tier perk due to the high utility of Fragmentation Grenades in Call of Duty 4. They are notably potent on smaller and/or linear maps, such as Showdown or Wet Work, due to the predictability of enemy paths. Common players simply spam their grenades without calculation when they either see an enemy at a distance and/or right when they spawn (otherwise: Grenade Mortaring), where as professionals would actually aim their grenades and use them sparingly. Either way using this perk is highly frowned upon, as some nicknames for the perk include "fag x3".

In Call of Duty: World At War, this perk is replaced by Primary Grenades x2 which, as the name implies, gives less grenades for balancing purposes. Primary Grenades x2 actually disables the user, as with other explosive Tier 1 Perks the user will have a total of 3 explosives, instead of only two. Arguably the versatility and power of grenades make up for the loss of one explosive, but the total firepower available is reduced.

In Call of Duty: Modern Warfare 2, Scavenger acts as a replacement for Frag x3. Due to the maximum of possessing only a single grenade at a time, the players' ability to grenade mortar from spawn to spawn is notably reduced. However Scavenger increases their potential amount of grenades per life. The limitation of grenades virtually eliminates the tactic of grenade mortaring, but does allow for other explosive-related tactics such as creating a practically unlimited set of claymores.

Strategy
The perk, although mostly used for grenade mortaring, can be useful for clearing out players Camping, especially if they are in an enclosed space. The perk is also useful for players trying to destroy Claymores or C4s, if they want to use grenades for human targets as well. However for this, Bomb Squad is more useful. Combined with Sonic Boom, this perk becomes incredibly deadly due to the increased blast radius of the three frags. In Search and Destroy, this is a useful perk compared with other Tier 1 perks such as Bandolier, as due to the short length of each round extra ammo is often not needed, and the extra grenades can help in killing enemies defending a planted bomb, or who are trying to defuse one.