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