Warp Door

Warp Doors are course elements that allow transport within one Sub-Area. They are placed in pairs, and when one is removed, the other is as well. In the editor, they are marked by one of the four playing-card symbols, allowing four sets of doors in each area - doors from the same pair have the same symbol.

They can be shaken to create other types of doors (both doors in a pair change when one is shaken)
 * The P-door, which looks like an outline at first, but becomes solid and usable when a P-switch is active.
 * The locked door, or key door, which you can spend a key to unlock.