Extradimensional Spaces Planar Binding Extradimensional spaces, for the purposes of spells that are limited to either the current plane or a specific plane, will be counted as an extra space that is a part of the plane it was opened on. For example, if you are on the prime material plane, and step into a portable hole, you would not be able to use plane shift to get back to the prime material, only other planes. Flooding If an extradimensional space is opened underwater, or submerged in another liquid, the liquid source fills the extradimensional space entirely. While Submerged,the liquid does not affect the capacity of the space, nor causes it to burst - it simply fills the bag or space as it would any other container. In the case of a compartmentalized space, such as Heward's Handy Haversack, only a single compartment would be filled. If there is space for a creature to enter, that creature must make a DC 15 Strength saving throw to avoid being sucked in by the rushing torrent. Any nonmagical parchment would be ruined, fires doused. Magical objects and items in sealed containers remain unharmed and undamaged.