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