Bomb Squad (14)
The Bomb Squad perk allows you to detect explosives planted in the map. This is useful if you are up against people who just love using bombs, and have C4 and Claymores hidden throughout the map. The Bomb Squad perk is unlocked at level 14 - Staff Sergeant I.
C4 Explosives x2 (2)
The C4 Explosives perk gives you two C4 explosives that you can detonate remotely using the fire button, or if you are using your primary weapon you can detonate them by double tapping the fire button. I find this a bit cumbersome with some weapons, but to each his own. In Call of Duty 4, there are no binoculars, so make sure you are aware of your enemyís location before setting them off - I find this also a bit difficult, but on some level night vision comes in handy. C4 Explosives are unlocked as soon as you unlock the Demolitions Class - level 2, Private I.
Claymore x 2
Claymores are basically a mine that you can plant in the game to blow people up when they are in range. The calymore packs use light sensors, and typical will be visible before you stumble upon one. The explosion is very directional, and because of this the Claymore perk isnít very useful in situations you would typically use mines. That said, Iíve had good luck hiding these things just around corners out of sight where people canít see the garish red beams emanating from these things. Claymores are unlocked at the onset of the game.
RPG-7 x 2
The RPG-7 x2 perk gives you two ground-to-air missiles that are very useful for shooting down helicopter air strikes. It should also be noted that they can explode cars and other destrutible objects on the map, and are very fun to shoot at spawn points, followed by a cooked nade.
Special Grenades x 3
This is my favorite among the Perk 1 group - this one gives you 3 special grenades as opposed to just one. Why is it my fave? Well, combine this with stun grenades, the radar, and the ďxĒ indication that youíve hit someone, and itís a great way to find out where people are, run up to them, and knife them with your hobo knife, even from far away! The Sepcial Grenades perk is unlocked by default.
Frag x 3 (41)
The Frag x3 perk gives you three frag grenades - simple huh? Not really, once this is unlocked, youíll find the maps littered with grenades - try as you will to pick them up and throw them back, more are on the way! This perk is unlocked at level 41 - Colonel I.
The Bandolier perk gives you much more amo for your clip, and is my second favorite among the Perk 1 set because it goes so well with the Double Tap perk. If you like to sprint around, doing some spray and pray while having a beer like me, this is definitely a must-try. The Bandolier perk is unlocked at level 32 - Captain I.
The Juggernaut perk, wellÖ makes you a juggernaut! You can take a LOT more damages than usual, and still be standing. Typically this means that I can survive 2 badly fought 1-on-1 rounds and still be running around like a chicken with my head cut off. This perk is unlocked straight away as far as I can tell.
Sleight of Hand (20)
Sleight of Hand helps you to reload weapons a lot faster, and if you canít aim, like to spray and pray, and run around without reloading or watching your amo, this may be for you. Truth be told, this comes in very handy for shotgun and SAW users, but just about any one can use this. Sleight of Hand is unlocked at Master Sergeant I (Lv20).
Stopping Power gives your weapon some oompf, and remoes the pew-pew! This is a good addition to weapons like the Mini Uzi, that while very fast, certainly lacks power. The Stopping Power perk is unlocked by default.
UAV Jammer (11)
The UAV Jammer perk helps to keep you off the radar, even when firing shots. This perk is useful against seasoned players who have become accustomed to watching the radar like hawks, and know all of the hiding places already. I highly recommend trying this with the Dead Silence perk and a knife. UAV Jammer is unlocked at level 11, Sergeant I.
The Sonic Boom perk gives your explosions some added range, and is great when used with the Martyrdom perk because it will see you taking out many people at a time as the grenade you drop will have a larger blast radius. This perk is unlocked out of the gates.
Easily the best perk in the game, Overkill allows you to carry two primary weapons at once, in the primary and secondary slots. This means you can fulfill your dreams of being a sniper/shotgunner! You simply change weapons to where your pistol would be, and thereís your other weapon. This is great because you can switch weapons faster than you can reload, in my case, but also because it opens the maps up so that everyone can carry an ACOG weapon as well as an LMG/SMG or what-have-you. Highly recommended, worth all of the effort.
Double Tap (29)
Double Tap increases the rate of fire for your weapon. This really helps balance things out for weapons that have a slow rate of fire, and makes some weapons like the M16 MUCH better. I highly recommend using this perk with the Bandolier perk as youíll be going through a lot more amo than usual. The Double Tap perk is unlocked at level 29 (1st Lieutenant I).
The Extreme Conditioning perk allows you to run for a much longer time, and is great in maps where you need to get to a certain point faster than someone else, or when you are trying to escape someone. The amount of time of the increase is roughly 2 times the normal sprint time. The Extreme Conditioning perk is unlocked for the get-go.
The Steady Aim perk give you better aim when not using iron sights or what-have-you. When you are running around in CoD4, your head and body bob, and affect your aim much more than in previous Call of Duty games. This perk restores some of the stability found in other CoD games, and makes aiming while running that much easier. This perk is unlocked already.
Last Stand (
Last stand gives you one last chance to shoot the person who killed you with your pistol sidearm. This can be useful on servers filled with beginners, but players are quickly getting used to finishing people of gangland-style because so many beginners are using this. Also, most medium to high ranked players will be using the Martyrdom perk, and since youíre only equipped with a pistol you can normally only tag people close to you, and once they die they drop a grenade and Ö well youíre dead. the Last Stand perk is unlocked early on, at Corpral II (Lv8).
A lot of weapons in CoD4 can now shoot through things like corrugated steel, boxes and thin walls. The Deep Impact perk emphasizes this, but also gives lower powered weapons a bit of a boost. Iíve had good results using this and the M16 and the P90. Deep Impact is unlocked by default, as far as I can tell.
Dead Silence (44)
The Dead Silence perk is one of my favorites because I love sneaking around maps stabbing people with my stabbing knife. Dead Silence makes you virtually silent, so that people donít hear floorboards creak as you walk up behind them wife your knife out just waiting to slash. Dead Silence is unlocked high level of 44, Brigadier General I, but is definitely worth it, and is amazing when combined with a silenced gun and UAV jamming. Or just use a knife!
Iron Lungs (26)
The Iron Lungs perk is interesting. The whole sniper class has caused quite a stir with Call of Duty fans because it is much harder to snipe in CoD4. This perk helps by allowing you to hold your breath longer, and keep the gun steady. Iím told the real trick to sniping in Call of Duty 4 is to have this perk, hold shift while you aim down the scope, and pause for just a half second longer than normal, and you will hit the mark everytime. Definitely worth trying with the Barret 50cal. Iron Lungs is unlocked at level 26 - 2nd Lieutenant I.
Eavesdrop is an interesting perk - it allows you to listen in on enemy chatter as you fight. Iím not sure how you canít hear them already, but this letís you hear them talking about their UAV as well as the bound speech items that some people use. Maybe they use microphones? Anyway, this is a great tool to use against those using stealth perks that make them hard to find on a map, and on the radar. The Eavesdrop perk is unlocked before the dead silence perk as well - you get it at level 35, Major I.
Martyrdom is one of the most popular perks, and also one of the most annoying. This perk lets you drop a live grenade just after dying, typically killing whoever just tore you up. This has people now sprinting away from corpses, as well as shooting at them just in case they have Last Stand instead. Because of this, if youíre sneaking up on someone who is about to kill someone, be prepared and have your pistol out to shoot them quickly before they run away. Also, if one of your team members has just killed the enemy in a closed room, be careful not to get caught in the door as you both run out. Finally, if you can, try picking up the dropped greande, and throw it at another enemy. Iíve only been able to do this in open spaces so far, and it needs to be done very quickly, but if youíve just done a slashing, youíll be right on top of the nade which makes things a bit easier. But you donít slash in wide open spaces, now, do you? Martyrdom is unlocked level 17 - Gunnery Sergeant I.