In an interview for Eurogamer, Rage creative director Tim Willits spoke of locking out some single-player content for people who bought the game used:

We have the first-time buyer stuff with all the sewers hatches, If you bought the game new, that would be open for you. You still have to download it, but you don’t have to pay for it. Those hatches are all over. Most people never find them. But as soon as you do, you’re like, oh. And then you start to look for it. That’s our first-time buyer incentive.

In simple words, Rage will not require an online Pass to unlock the multiplayer mode (that would be a code that comes with new copies, or bought online for a fee). Instead, used copies of Rage will lock some sewers hatches in the single-player campaign which are the paths needed to enter new missions in the campaign and a “thank you” to players who bought a new copy of Rage!

Rage is set to launch on the PlayStation 3, Xbox 360 and PC on October 4 2011.