Left 4 Dead

Achievements:
Complete the following achievements to award the indicated amount
of Xbox Live Gamerscore points.

Stomach Upset (20 gamerscore points):
All Survivors finish a campaign without being vomited on.

Lamb 2 Slaughter (20 gamerscore points):
As an Infected, incap a Survivor who has entered and left a safe room.

No-one Left Behind (20 gamerscore points):
Complete a campaign with all 4 Survivors.

Pyrotechnician (20 gamerscore points):
Blow up 20 Infected in a single explosion.

Chain Smoker (20 gamerscore points):
Constrict two Survivors in one life as a Smoker.

Barf Bagged (20 gamerscore points):
Cover four Survivors with Boomer bile at once.

Dead Wreckening (20 gamerscore points):
Dole out 5000 total Survivor damage as a Special Infected.

Big Drag (20 gamerscore points):
Drag a Survivor 100 feet with your tongue.

Unbreakable (30 gamerscore points):
Complete a campaign without ever being healed.

Tongue Twister (20 gamerscore points):
Free yourself from a Smoker who has grabbed you with his tongue.

Pharm-assist (20 gamerscore points):
Give pain pills to 10 Survivors.

Jump Shot (20 gamerscore points):
Headshot a Hunter while he's leaping.

Field Medic (20 gamerscore points):
Use the Heal first aid kit to heal 25 Survivors.

Dead Giveaway (10 gamerscore points):
Heal a fellow Survivor when your own health is below 10.

No Smoking Section (15 gamerscore points):
Execute 10 Smokers as they are pulling helpless Survivors.

Red Mist (20 gamerscore points):
Execute 1000 Infected with a mounted machine gun.

Zombie Genocidest (20 gamerscore points):
Execute 53,595 Infected.

Tankbusters (20 gamerscore points):
Destroy a Tank without it dealing any damage to a Survivor.

Cr0wnd (30 gamerscore points):
Execute a Witch with a single headshot.

Witch Hunter (20 gamerscore points):
Execute a Witch without any Survivor taking damage from her.

All 4 Dead (30 gamerscore points):
Execute all 4 Survivors in one life while playing as a Tank.

Spinal Tap (10 gamerscore points):
Execute an Infected with a single blow from behind.

Back 2 Help (20 gamerscore points):
Leave a safe room to save an incapped teammate and bring them back safely.

Towering Inferno (10 gamerscore points):
Light a Tank with a Molotov.

Burn the Witch (10 gamerscore points):
Light a Witch with a Molotov.

Brain Salad (15 gamerscore points):
Perform 100 headshot kills.

Untouchables (30 gamerscore points):
No Survivors take damage after contacting the rescue vehicle.

Safety First (30 gamerscore points):
Play an entire campaign with no Survivors taking friendly fire damage.

Double Jump (20 gamerscore points):
Pounce two different Survivors in one life as a Hunter.

My Bodyguard (15 gamerscore points):
Protect any Survivor from an attacking Infected 50 times.

Dead Stop (10 gamerscore points):
Punch a Hunter as he is pouncing.

Drag and Drop (20 gamerscore points):
Rescue a Survivor from a Smoker's tongue before he takes damage.

Hero Closet (10 gamerscore points):
Rescue a Survivor trapped in a closet.

Helping Hand (20 gamerscore points):
Revive 50 incapacitated Survivors.

Ground Cover (30 gamerscore points):
Save another Survivor from a Special Infected while on the ground.

101 Cremations (20 gamerscore points):
Set 101 Infected on fire.

Clean Kill (10 gamerscore points):
Shove a Boomer and then kill him without him splashing on anyone.

Hunter Punter (10 gamerscore points):
Shove a Hunter off of a pinned and helpless Survivor.

Man vs Tank (30 gamerscore points):
Single-handedly kill a Tank.

Do Not Disturb (20 gamerscore points):
Sneak past all Witches in a campaign without disturbing one.

Nothing Special (30 gamerscore points):
Survive a campaign with no Survivors taking damage from Special Infected.

Stand Tall (20 gamerscore points):
Survive a campaign without being incapacitated.

What Are You Trying to Prove? (35 gamerscore points):
Survive all campaigns on Expert difficulty level.

Akimbo Assassin (30 gamerscore points):
Survive an entire campaign using only pistols.

Zombicidal Maniac (30 gamerscore points):
Survive any campaign on Expert difficulty level.

Grim Reaper (15 gamerscore points):
Survive the Blood Harvest campaign.

Dead Baron (15 gamerscore points):
Survive the Dead Air campaign.

Toll Collector (15 gamerscore points):
Survive the Death Toll campaign.

Mercy Killer (15 gamerscore points):
Survive the No Mercy campaign.

Blind Luck (20 gamerscore points):
You or another Survivor take no damage after being vomited on by a Boomer.