Running Steam game in fullscreen doesn't allow second screen to show anything else (Mavericks) In Mavericks, when I'm running a full screen game, the second screen can't show desktop (or browser, or anything else.)  My understanding is that Mavericks sets the second screen in a different Space so both can be used.  Am I doing something wrong or is that a wrong understanding?
I believe Steam uses its own full-screen mechanism independent of the system's full-screen option.  Since it's not the typical full-screen provided by OS X, the multiple spaces feature doesn't work here.