I finished a universal iOS game that is meant to be played in landscape orientation. In Xcode's target editor I deselected the checkboxes for Portrait and Upside Down orientations. Deselecting the checkboxes forces the iPhone version to be played in landscape orientation but not the iPad version.
I saw the Info.plist file has a field called Supported device orientations (iPad). It supports all four orientations initially. I removed the two entries for portrait orientation. When I submitted my build to the App Store, it was rejected for not supporting portrait orientation on the iPad. The error message said that iPad multitasking requires support for all four orientations.
I added the entries for portrait orientation back to the Info.plist file. I submitted the game to Apple for review. They rejected the game because it doesn't play right on iPad in portrait orientation.
How do I require an iOS game to be played in landscape orientation on both iPhone and iPad?
To force landscape orientation on the iPad, you must require full screen for the app. Select the Requires full screen checkbox for the target in the project editor.
Requiring full screen turns off support for iPad multitasking. After requiring full screen, you can remove portrait from the iPad supported device orientations in the Info.plist file.