Get some extra equipment by going to the the Multiplayer 'Main' menu and selecting the 'Enter Code' option. Then input the following codes without the quotes to get the corresponding kit.

Unlock QBU88 Recon Kit (Sniper Rifle):
Enter the code 'your3mynextt4rget'.

Unlock the M60 Support Kit (Machine Gun):
Enter the code 'try4ndrunf0rcov3r'.

Unlock the Uzi Special Ops Kit (Machine Gun:
Enter the code 'cov3r1ngthecorn3r'.

These are earned in Multiplayer mode by completing the indicated task.

Unlock Destruction Site Wildcard:
Destroy 50 objects in a round.

Unlock Dueces are Wild Wildcard:
Kill 2 enemies of each kit in a round.

Unlock Five of a Kind Wildcard:
Destroy 5 vehicles of the same kind in a round.

Unlock Snake Eyes Wildcard:
Get 11 kills as 2 different classes in a round.

Unlock Staying Dry Wildcard:
With a sea vehicle get 2 seconds air time in a round.

Unlock Airtime Wildcard:
In a land vehicle get 2 seconds air time in a round.

Unlock Straight Flush Wildcard:
Destroy 1 vehicle of each kind in a round.

Unlock Full House Wildcard:
Destroy 3+2 vehicles of the same kind in a round.

Unlock Gunslinger Wildcard:
In Global get 80 kills with a handgun.

Unlock Santa's Litle Helper Wildcard:
Get 10 Kill Assists Points in a round.

Unlock Headshots Wildcard:
Get 20 kills from headshots in a round.

Unlock Squad Avenger Card Wildcard:
In Global get 100 Avenger Points avenging squad members.

Unlock Parashooter Wildcard:
Get 4 road kills with any air vehicle in a round.

Unlock Cab Driver Wildcard:
Spend 5 minutes in a round as a driver in a vehicle with passengers.

Unlock 1 On 1 Land Wildcard:
Destroy 1 land vehicle of the same kind without assistance in a round.

Unlock 1 On 1 Sea Wildcard:
Destroy one sea vehicle of the same kind without assistance in a round.

Unlock 1 On 1 Air Wildcard:
Destroy an air vehicle of the same kind without assistance in a round.

Unlock Chopper Chopper Kills Wildcard:
Destroy 5 air vehicles in a round.

Unlock Dead Eye Headshots Wildcard:
In Global get 100 headshots with any sniper rifle.

Unlock Squad Wild Card Wildcard:
Get 1 Squad Member trophy per squad member in a round.

Unlock Strike Wildcard:
Kill 10 enemies at the same time in a round.

Unlock Tank Buster Wildcard:
Destroy 5 tanks in a round.

Unlock Three Of A Kind Wildcard:
Destroy 3 vehicles of the same kind in a round.

Unlock Armor Buster Wildcard:
Destroy 5 armored vehicles in a round.

Unlock Savior Trophies Wildcard:
In Global collect 50x Savior Trophies.

Unlock Avenger Trophies Wildcard:
In Global collect 50x Avenger Trophies.

Unlock Beat the House Wildcard:
Get 15 grenade kills in a round.

Unlock 2 Pair Wildcard:
Get 2 of any 2 trophies in a round.

Unlock Full Deck Wildcard:
Get 52 total kills in a round.

Save time looking for items and weapons by accessing the map and looking for 'X's as these indicate their location. Also search near the 'X's as sometimes there will be gold pickup spots there.

Trophies are obtained when you play Multiplayer mode and complete certain tasks. Listed alphabetically below are the trophies along with the corresponding task.

Unlock Assault Rifle Efficiency Trophy:
Get 6 kills with an assault rifle in a round.

Unlock Avenger Trophy:
Get 3 Avenger Points in a round.

Unlock Best Squad Trophy:
Awarded at the end of a round.

Unlock Big Guns Trophy:
Get 5 kills with artillery in a round.

Unlock Carbine Efficiency Trophy:
Get 6 kills with a M16A2 in a round.

Unlock Clear Skies Trophy:
Get 5 kills with a stationary weapon in a round.

Unlock Combat Aviator Trophy:
Get 5 kills with an air vehicle in a round.

Unlock Combat Efficiency Trophy:
Get a 6 kill streak in a round.

Unlock Combat Engineer Trophy:
Get 20 vehicle repair points (2 repairs) in a round.

Unlock Compact Assault Rifle Efficiency Trophy:
Get 6 kills with a compact assault rifle in a round.

Unlock Demo Pack Efficiency Trophy:
Get 3 kills with C4 in a round.

Unlock Emplacement Trophy:
Get 5 kills with a stationary weapon in a round.

Unlock Explosive Efficiency Trophy:
Get 10 kills with explosives in a round.

Unlock Firearm Efficiency Trophy:
Get 3 kills with a handgun in a round.

Unlock Frag Out Efficiency Trophy:
While playing Demolitionists get 3 kills with a grenade in a round.

Unlock Grenade Launcher Efficiency Trophy:
Get 6 kills with a grenade launcher in a round.

Unlock Grenadier Efficiency Trophy:
While playing Assault get 3 kills using grenades in a round.

Unlock High Card Trophy:
Get the best IAR Score in a round.

Unlock Kill Assists Trophy:
Get 5 kill assists in a round.

Unlock Laser Designating Efficiency Trophy:
From laser designating get 3 kills in a round.

Unlock Ligh Machinegun Efficiency Trophy:
Get 6 kills with a light machinegun in a round.

Unlock Marksman Trophy:
Get 5 kills with a sniper rifle in a round.

Unlock Medic Trophy:
Get 10 points from Medkit (2 heals) in a round.

Unlock Melee Combat Trophy:
Get 5 melee kills in a round.

Unlock Mine Placement Efficiency Trophy:
Get 3 kills with mines in a round.

Unlock Mortar Strike Efficiency Trophy:
Get 3 kills with a mortar strike in a round.

Unlock Naval Surface Warfare Trophy:
Get 5 kills with a sea vehicle in a round.

Unlock Objective Attack Trophy:
Destroy the last objective in a round.

Unlock Objective Defender Trophy:
Get 30 Defend Points in a round.

Unlock Objective Destroyer Trophy:
Destroy 3 objectives in a round.

Unlock Rocket Launcher Efficiency Trophy:
In a round, get 3 kills with a rocket launcher.

Unlock Savior Trophy:
Get 3 Savior Points in a round.

Unlock Shotgun Efficiency Trophy:
Get 5 kills with a shotgun in a round.

Unlock Squad Medication Trophy:
Get 40 Squad Member Heal Points in a round.

Unlock Squad Member Trophy:
Get 5 assists or save 5 squad members in a round.

Unlock SVU Efficiency Trophy:
Get 5 kills with the SVU in a round.

Unlock Tank Warfare Trophy:
Get 5 kills with tanks in a round.

Unlock Target Tagging Efficiency Trophy:
Get 2 Kill Assists from Dartgun Tagging in a round.

Unlock Transport Vehicle Trophy:
Get 5 kills with a transport vehicle in a round.

Unlock UMP Trophy:
Get 6 kills with a UMP in a round.

Unlock Wheels Of Hazard Trophy:
Get 2 road kills in a round.

Unlock Winning Team Trophy:
Awarded at the end of a round.

Get the following weapons in your arsenal by completing the indicated task.

Unlock QBU-88 Sniper Rifle:
Unlocked through a unique code which was provided if the game was pre-ordered before June 23rd, 2008.

Unlock Uzi:
Download the 'Battlefield: Bad Company' demo version and then select the 'Quick Match' option. Then play a ranked match and get over 23,000 EXP to reach Rank 4.

Unlock USAS-12 Semi-Automatic Shotgun:
When you view your multiplayer stats online this weapon will be available the next time you sign into the game.

Unlock F2000 Assault Rifle:
Register your old Battlefield games at http://www.veteran.battlefield.com/

Unlock M60:
Visit the website findallfive.com and select the 'Join the Battlefield Community' option and sign up with Electronic Arts. When you then register for the 'Battlefield: Bad Company e-mail newsletter' you will receive a unique code by e-mail which will enable you to unlock this destructive weapon.