Full list of all 101 Left 4 Dead 2 achievements. It takes around 80-100 hours to unlock all of the achievements in the base game on Windows.
The base game contains 52 achievements, and there are 7 DLC packs containing 49 achievements.
Form a team and beat an enemy team in 4v4 Versus or Scavenge.
Make a Survivor drop a gas can during overtime.
Cause 25 gas can drops as a Special Infected.
In a Versus round, leave the saferoom to defibrillate a dead teammate.
Collect 100 gas cans in Scavenge.
Revive 10 incapacitated Survivors while under the speed-boosting effects of adrenaline.
Revive 10 dead Survivors with the defibrillator.
As the Jockey, ride a Survivor for more than 12 seconds.
As the Charger, bowl through the entire enemy team in a single charge.
As the Jockey, ride a Survivor and steer them into a Spitter's acid patch.
As the Spitter, spit on a Survivor being choked by a Smoker.
Survive all campaigns on Expert.
Using a Molotov, burn a Clown leading at least 10 Common Infected.
In a Survival round, get a medal only using melee weapons.
Kill a Charger with a melee weapon while they are charging.
As the Charger, grab a Survivor and carry them over 80 feet.
Win a game of Scavenge.
As the Spitter, hit every Survivor with a single acid patch.
Stop the enemy team from collecting any gas cans during a Scavenge round.
As the Charger, grab a Survivor and smash them into the ground for a solid 15 seconds.
As the Jockey, ride the Survivors twice in a single life.
Finish a campaign using only melee weapons.
Defend yourself at the crashed airliner without taking damage.
Cross the bridge finale in less than three minutes.
Navigate the impound lot and reach the cemetery safe room without tripping any alarms.
Collect 10 vials of Boomer vomit from infected CEDA agents you have killed.
Survive a campaign on Expert skill with Realism mode enabled.
Ignite 50 Common Infected with incendiary ammo.
Collect 15 gas cans in a single Scavenge round.
Kill 10 swampy Mudmen while they are in the water.
Decapitate 200 Infected with a melee weapon.
Use every melee weapon to kill Common Infected.
Prove you are faster than Moustachio.
Prove you are stronger than Moustachio.
Survive the Hard Rain campaign.
Navigate the sugar mill and reach the safe room without killing any Witches.
Plays games with free weekend players and helps them survive a campaign.
Survive the Swamp Fever campaign.
Survive the Dark Carnival campaign.
Rescue Gnome Chompski from the Carnival.
Kill 100 Common Infected with the chainsaw.
Survive the Dead Center campaign.
Deploy an ammo upgrade and have your team use it.
Kill a Jockey within 2 seconds of it jumping on a Survivor.
Survive the Parish campaign.
Honk the noses of 10 Clowns.
Kill one of each Uncommon Infected.
Kill a Tank with melee weapons.
Use a bile bomb on a Tank.
Kill 15 Infected with a single grenade launcher blast.
Kill a Spitter before she is able to spit.
Spread cheer by helping a free holiday player survive a campaign.
Play 5 full games of Scavenge on The Port.
As the Charger, grab a Survivor and crash them through 8 chairs at the wedding.
Kill a Tank only with damage from the original Survivors.
Play 6 Mutations.
Collect 10 items dropped by a Fallen Survivor.
Survive The Passing Campaign.
Open 5 foot lockers.
Knock off the heads of 18 infected with the golf club.
Play the new Midnight Riders song on a jukebox.
Using the M60, kill 25 infected without letting go of the trigger.
Have all 3 generators running at once in "The Sacrifice" finale.
As a Special Infected, incap someone who is trying to sacrifice themselves.
Kill a Special Infected with an exploding barrel.
Have Bill sacrifice himself for the team.
Complete "The Sacrifice".
Survive the Cold Stream campaign on any difficulty.
Play a Versus game on Dead Air from start to finish.
Collect three gifts dropped by Special Infected in Versus Mode.
Kill 53,599 infected. You made sure the dead won't rise anymore!
Destroy 20 gascans as the Spitter.
Rescue three Survivors from a single rescue closet.
As the Spitter, spit on a Survivor who is pinned by a Charger.
Kill the Witch bride with a single shotgun blast on expert difficulty.
Kill 20 Jockeys with the shovel or pitchfork.
Survive for 10 minutes on any official map in Versus Survival.
Earn a gold medal on every official survival map.
Earn a silver medal on every official survival map.
Earn a bronze medal on every official survival map
On the concert finale, survive until the helicopter arrives without leaving the stage
Survive for 30 minutes on any official survival map.
Complete The Last Stand campaign in 13 minutes or less, without any Survivors dying.
Kill a Witch using only a sharp melee weapon, without anyone getting incapacitated or killed.
With a sharp melee weapon, cut a Smoker's tongue before he ensnares you.
Instantly kill a Survivor as the Charger.
As the Hunter, land a 25 damage pounce.
Find the golden crowbars hidden in the Left 4 Dead 1 survival maps.
Earn a gold medal on any official survival map.
Escape Liberty Mall's Atrium before the first Tank appears
Survive The Last Stand campaign on Expert Realism.
Destroy a Tank's rock in mid-air.
As the Boomer, vomit on a Survivor without having direct line of sight with them.
As the Spitter, spit on a Survivor who is pinned by a Hunter.
Discover the hidden room in the Last Stand campaign
Earn a silver medal on any official survival map.
Revive an incapacitated teammate while a Tank is nearby.
Survive The Last Stand campaign on any difficulty.
Kill a pouncing Hunter with a shotgun.
Earn a bronze medal on any official Survival map.
If you are reading this achievement, Gabe Newell has successfully launched Gnome Chompski into space.