Kill a Spitter before she is able to spit.
A RIDE DENIED
Kill a Jockey within 2 seconds of it jumping on a Survivor.
ARMORY OF ONE
Deploy an ammo upgrade and have your team use it.
Kill one of each Uncommon Infected.
Survive the Dead Center campaign.
Use a bile bomb on a Tank.
CHAIN OF COMMAND
Kill 100 Common Infected with the chainsaw.
Ignite 50 Common Infected with incendiary ammo.
Survive The Passing Campaign.
Decapitate 200 Infected with a melee weapon.
Survive the Dark Carnival campaign.
As the Spitter, hit every Survivor with a single acid patch.
As the Jockey, ride a Survivor for more than 12 seconds.
BACK IN THE SADDLE
As the Jockey, ride the Survivors twice in a single life.
Use every melee weapon to kill Common Infected.
Survive the Hard Rain campaign.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
Survive the Parish campaign.
Survive the Swamp Fever campaign.
RODE HARD, PUT AWAY WET
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
Complete "The Sacrifice".
KILLING THEM SWIFTLY TO THIS SONG
Play the new Midnight Riders song on a jukebox.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
DEAD IN THE WATER
Kill 10 swampy Mudmen while they are in the water.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
A SPITTLE HELP FROM MY FRIENDS
As the Spitter, spit on a Survivor being choked by a Smoker.
Have Bill sacrifice himself for the team.
Kill 15 Infected with a single grenade launcher blast.
LONG DISTANCE CARRIER
As the Charger, grab a Survivor and carry them over 80 feet.
Survive the Cold Stream campaign on any difficulty.
Honk the noses of 10 Clowns.
Collect 10 items dropped by a Fallen Survivor.
KITE LIKE A MAN
Kill a Tank only with damage from the original Survivors.
Open 5 foot lockers.
VIOLENCE IN SILENCE
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Knock off the heads of 18 infected with the golf club.
Valve Gift Grab 2011 – L4D2
Collect three gifts dropped by Special Infected in Versus Mode.
GHOST OF CHRISTMAS PRESENT
Spread cheer by helping a free holiday player survive a campaign.
Win a game of Scavenge.
Prove you are faster than Moustachio.
Stop the enemy team from collecting any gas cans during a Scavenge round.
LEVEL A CHARGE
Kill a Charger with a melee weapon while they are charging.
Rescue Gnome Chompski from the Carnival.
As the Charger, bowl through the entire enemy team in a single charge.
Kill a Tank with melee weapons.
TIL IT GOES CLICK
Using the M60, kill 25 infected without letting go of the trigger.
CACHE AND CARRY
Collect 15 gas cans in a single Scavenge round.
Prove you are stronger than Moustachio.
Navigate the sugar mill and reach the safe room without killing any Witches.
Have all 3 generators running at once in "The Sacrifice" finale.
Kill a Special Infected with an exploding barrel.
Revive 10 dead Survivors with the defibrillator.
Make a Survivor drop a gas can during overtime.
BRIDGE OVER TREBLED SLAUGHTER
Cross the bridge finale in less than three minutes.
CONFEDERACY OF CRUNCHES
Finish a campaign using only melee weapons.
Play a Versus game on Dead Air from start to finish.
Play 6 Mutations.
WING AND A PRAYER
Defend yourself at the crashed airliner without taking damage.
THE QUICK AND THE DEAD
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
BEAT THE RUSH
In a Survival round, get a medal only using melee weapons.
Collect 100 gas cans in Scavenge.
Cause 25 gas can drops as a Special Infected.
THE REAL DEAL
Survive a campaign on Expert skill with Realism mode enabled.
STILL SOMETHING TO PROVE
Survive all campaigns on Expert.
GOOD GUY NICK
Plays games with free weekend players and helps them survive a campaign.
STRENGTH IN NUMBERS
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
PORT OF SCAVENGE
Play 5 full games of Scavenge on The Port.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
As a Special Infected, incap someone who is trying to sacrifice themselves.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.