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