No Mercy is the first campaign in the Left 4 Dead series. It begins after the opening clip which ends with the survivors miraculous escape from total peril on the roof of an apartment building. Here, the Survivors hear a message from a hovering helicopter saying, "To anyone who can hear this, proceed to Mercy Hospital for evacuation." The campaign tracks the Survivors' progress from the apartment rooftop, all the way to the top of Mercy Hospital, where they are eventually rescued.
- Chapter List
 Survival Mode Maps
These are the survival maps for the campaign No Mercy.