In Dungeons & Dragons and in cartoon physics, a portable hole is a magical device that can be used to contravene the normal laws of physics. It resembled a circular black cloth that could be placed on a surface to create a hole. If placed on a wall, the user could then crawl through the hole and come out on the other side. If placed on the ground, the user could place objects in the ground, as if he had dug a hole, and then remove the portable hole, causing them to be buried where the hole was placed. Players could also use them as foxholes if they wished.

Portable holes were categorized by the circumference of their opening and their depth. Thus, a hole with a 1 foot circumference and 3 foot depth wouldn’t be suitable for breaching a wall, but perfectly fine for burying some small treasure.

Some dungeonmasters allowed them to be used as weapons, saying that if the hole was affixed to a living being it would cause whatever innards it covered to spill out. Also, a living being put into the ground via a portable hole would be buried alive and die of suffocation.

Like a bag of holding, other portable holes, bags of holding or extra dimensional spaces placed in it would cause catastrophic results at the DM’s discretion.

Portable holes are not part of the Dungeons & Dragons Third Edition core rules, but they may exist in expansions and supplements.

Portable holes are sometimes used in Looney Tunes cartoons, including such variations as foldable doorways. One is used to great effect in the movie Who Framed Roger Rabbit. In Yellow Submarine, Ringo also had a portable hole in his pocket.