No Mercy

No Mercy
Tagline	"Curing the Infection... One bullet at a time."
Creator	Valve Software
Chapters	The Apartments The Subway The Sewer The Hospital Rooftop Finale

"Make your way to Mercy Hospital for a rooftop rescue."

No Mercy is the first campaign in Left 4 Dead and spans five levels.

The first level picks up where the game's introduction cutscene leaves off. The Survivors hear from a passing rescue helicopter they can be evacuated if they make their way to Mercy Hospital. On their trek to safety they encounter Infected-filled apartment buildings, city streets, subway tunnels, and sewers. They discover that Mercy Hospital has been overrun but that there is still a chance of rescue if they can fight their way to the helicopter landing pad on the roof of the hospital.

Below is a complete list of video walkthroughs of the 5 levels:

1. The Apartments
2. The Subway
3. The Sewer Parts 1
   and 2
4. The Hospital
5. Rooftop Finale

Please know that the gameplay videos are on each campaign's info page not on each map page.

Official description

The No Mercy campaign finds you on the rooftop of an obliterated apartment complex, deep in the heart of the once-thriving metropolis of Fairfield—now completely overrun with hordes of Infected. A voice from a bullhorn calls out from a rescue helicopter: Get to the roof of nearby Mercy Hospital and be airlifted to safety. Even if it means shooting your way through narrow alleys, open sewers and seething waves of zombies to get there.

Left 4 Dead 2

With [[The Sacrifice] and Cold Stream DLCs, No Mercy was edited and ported over to Left 4 Dead 2. Thus it included all the new Infected, items and weapons giving a whole new experience. Video walkthroughs made by youtuber Rusty Woud show off the Left 4 Dead 2 version of the campaign and all the changes:

1. Maps 1 and 2
2. Map 3
3. Maps 4 and 5

Graffiti

Writings on the wall at the end of The Subway.

The Apartments level contains plentiful graffiti. Much of it is located in the safe room and on walls along the way.

The captions are of a despairing nature, for instance, "Hope" is spray painted in large letters to the left of the doorway but someone has added "NO" above it to change it to say "No Hope". "Morbid", "None of you will survive", and "Entire city is Infected, if you can read this, get out" add to the aura of hopelessness.

In the finale, a clue as to Green Flu's nature is provided a written conversation on the wall recording the rapidly condensing passage of time between being bitten and turning into an Infected falling from 5 days to 3 days, 1 day, 2 1/2 hours, and then finally 5 minutes.

Demo

The Left 4 Dead demo consisted of The Apartments in its entirety, as well as most of The Subway. The rest of the Subway map could be seen in the demo if players went into Noclip mode.

Achievements

See Main Article: Achievements

The following Achievements are only available after beating the campaign.

	MERCY KILLER	(15G)
	Survive the No Mercy campaign.

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	ZOMBICIDAL MANIAC	(30G)
	Survive any campaign on Expert.

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	WHAT ARE YOU TRYING TO PROVE?	(35G)
	Survive all campaigns on Expert.

Behind the Scenes

No Mercy's lightling effects underwent marked changes during development. Early on, the contrast between light and shade was accentuated. Ambient light in each scene was suppressed making for a dark and ill-lit enviroment and where there was a light, it was made extremely bright.

Skyscrapers and other buildings in the background appeared unnaturally flat because they were a part of the skybox texture. Since this does not affect gameplay, this may have been done deliberately to speed up the game's development for playtesting purposes. In the final version buildings are rendered as actual brushes and models.

The sky was once a dark blue as compared to the blue/green mix in the final version.

Buildings had most of their lights on. In the final version, only scattered windows are illuminated.

More contrast and the dark blue sky.

Dark blue sky and most of the lights in the buildings are on.

Notice that the buildings are completely flat; this is because they are a part of the skybox texture.

Notes

A map of the campaign which spans from The Apartments to Rooftop Finale.

• The working title for this campaign was "Hell Hospital."
• In common with many other maps in the game, the sound of sporadic machine gun fire can be heard from time to time in the distance. This is evidence that there are other survivors 'out there' in similar straits to those experienced by Bill, Zoey, Louis and Francis. This fact is reinforced subsequently by safe room graffiti and character dialog indicating that the Survivors are following similiar escape routes to others who have preceded them.
• In the game's files, there is unused sound and graphics codes for the Chopper Pilot, for example there is a sound file which has him skyshouting: "Hey down there! I can't get any closer, but if you can get to Mercy Hospital I can take ya to the military outpost up north. You have to get to Mercy Hospital! Call me on the radio when you get there.". In another such file has him saying to go to Mercy Hospital because he will no longer risk street level pick-ups after having been attacked and bitten earlier. These files ended up on the cutting room floor as a direct result of Valve changing the campaign's ending in response to playtesting feedback.
• The rooftop location of Mercy Hospital's helipad is unusual for this part of the United States. High wind conditions and low cloud and snow in winter would render this facility unusable and unsafe for the light helicopters typically used for medical rescue services.
• Fairfield (2010: pop 507) is a real town in southern Pennsylvania located just outside Gettysburg.
• Similar to Death Toll's poster, Bill's beret and handling of his weapon are inverted horizontally.
• In the Left 4 Dead 2 port, there are many more spawn points for guns compared to the original version in Left 4 Dead. There are also the Left 4 Dead 2 exclusive weapons, such as the Grenade Launcher, M60 and melee weapons. There are also Worker Infected and CEDA Worker Infected for the third and fourth maps of the campaign.
• The Left 4 Dead 2 port contains a number of changes, some of which appears to be based from the Versus maps of No Mercy:
  • In The Subway, a dead man with a suit and tie is replaced by a bloody dead police ragdoll.
  • All of the patient ragdolls in The Hospital were also replaced by dead police ragdolls.
  • Workman and CEDA infected are added to the enemy's ranks.
  • Bile Jars are encountered for the first time in association with the CEDA infected found in Mercy Hospital's forecourt area.
  • There are subtle changes to the hospital's breakable walls on the elevator floor.
  • Bonus supplies such as laser sights or special ammo are invariably provided in the last room on the left in the elevator passage.
  • The starting building in The Apartments has had the A/C units removed from the wall behind the building, preventing a previous exploit that allowed Survivors to skip the first building completely.
  • The Rooftop Finale changes relative to Left 4 Dead include:
    • A railing now prevents Charger insta-kills off the roof edge of the building that gives direct access to the hospital roof.
    • There is a significantly greater number of Common Infected loitering on the various roof spaces at the start.
    • The radio room features subtle changes to the placement of doors and windows, the closet has been removed,  health packs and ammo have been moved to the roof and the stairs are now unenclosed (much like the Versus version of this campaign). Cumulatively, these revisions actively discourage players from fighting the finale from inside the radio room; a tactic that is very effective in Left 4 Dead series one.
    • Explosive supplies and grenades are offered in more generous quantities.
    • At least one Grenade Launcher (sometimes even two) is provided on a rooftop structure opposite the radio building.
    • When playing Single Player, bots stay closer to the human player and do not stray off during the finale.
  • The elevator's overhead emergency and service panel has been closed, most likely to prevent Spitter attack.