Valve Software said Tuesday that Left 4 Dead pre-order customers will have first access to a demo for the zombified shooter.

Advance access for the demo will begin November 6 for those who pre-ordered the game via Steam on PC or at participating retailers in North America. On November 11, the demo will be available for all Xbox 360 and PC gamers who didn't pre-order.

The demo will allow for 1-4 players, and cease when the game launches on November 18.

The early peek is part of the $10 million advertising campaign revealed to Edge earlier this month.

"Every time someone plays Left 4 Dead, we witness the most overwhelmingly positive reaction that we've seen from any of our games," said Gabe Newell, president and co-founder of Valve in a statement.

"This gives us tremendous confidence in the product and why we've taken the game on the road, produced this pre-launch demo, and invested more advertising dollars on the title than any prior release from Valve."