Expansive Space

You touch a container, such as a backpack, satchel, or chest, and cause its contents to expand inward.

The container you touch is able to hold up to 600 pounds more than it could when it was mundane, not exceeding a volume of 100 cubic feet, and weighs 15 pounds regardless of its contents. You choose what you see when you look through the container's opening - you could see the starry expanse of the Astral Sea, a sea of organized shelves that hold the container's contents, or another such scene, at your discretion and subject to the DM's approval.

If you overload your container by placing too many items into it, you are stopped from placing anything into the container. If the container is ripped, torn, or is otherwise destroyed, its contents are scattered to the Astral Plane, and are otherwise irretrievable. If you place a container you create with this spell into a container that uses this spell, such as a Bag of Holding or Heward's Handy Haversack, or into a Portable Hole, you cause both spaces to be destroyed, and all creatures within 100 ft. of you (including you) must make a Charisma saving throw against your spell save DC. On a failure, a creature takes 10d10 Force damage and is shunted into the Astral Plane.

If you cast this spell on an item that already hosts an extradimensional space (such as a Bag of Holding), then you cause its total space to expand to twice as much as it could hold normally. You can only cast this spell in this way once for that specific container - any more, and all creatures within 100 ft. of you (including you) must make the Charisma saving throw, as above, and the container is destroyed.

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the container you touch can hold an additional 100 pounds worth of items per level of spell slot above 5th.