Left 4 Dead: Survive Finale in Seconds

AntMag.NET

This is a slick strategy for the No Mercy finale that'll help you take almost no damage. Make sure everyone's topped off on health and ammo, and at least one person has a Pipe Bomb ready.

Walkthrough

1
As soon as you radio for help, immediately book it out of the room. Get all the way underneath the metal ramp leading up to the helipad. You'll need to crouch to get all the way to the back.
2
Once you're under there, all the Infected will funnel through the single entrance to your spot, and they won't be able to hit you, even if they're above you or on the other side of the piping. Keep a close eye out for Smokers, though!
3
When the Tank shows up, everyone needs to focus fire on it to bring it down fast. If you don't, it'll wreck your team.
4
Repeat step 3 for the second wave of Infected.
5
After you've dealt with the second Tank, you'll hear that the helicopter has arrived. As soon as you hear it, run up to the helipad.
6
Take your Pipe Bomb and toss it back down the ramp. This should keep the horde off your back until the helicopter door opens.
7
As soon as the door opens, jump in to safety!