Worldwalk

Worldwalk was an arcane alteration spell that could connect the plane of the caster to another plane or dimension, allowing two-way travel between them.

Effects
This spell could be cast into an open area or against a wall up to 90 ft (27 m) away, as long as the space was not occupied. It created a round portal up to 20 ft (6.1 m) in diameter that could be oriented either horizontally or vertically with respect to the caster. One side of the portal was a featureless gray and the other side gave a two-way view into the connected plane. Once established, the portal lasted for at least two hours and creatures could pass through the portal in either direction at a rate of about one per minute. Creatures that could not fit through the circular gateway could not pass unless they were physically reduced in size somehow.

Only living beings could pass through a worldwalk portal. Non-living objects and material could not pass unless it was carried by a living creature. Thus, a portal between the Elemental Plane of Water and the Elemental Plane of Fire would be perfectly safe and creatures on either side would not be exposed to harm until they actually passed through. If a creature was caught in the portal at the time of its collapse, either by the will of the caster, a successful dispel magic, or the expiration of the spell's duration, that creature was immediately dumped onto the plane of Concordant Opposition, also known as the Outlands.

When casting this spell, the caster had to visualize a destination known to him or her by personal experience. Alternatively, if an object from the desired plane was available, it could be used as the link to cast worldwalk to a plane the caster had never visited. The object became a material component of the spell, but was not consumed or harmed by the casting. There was a small but significant chance that worldwalk would not connect to the desired plane, but to some other plane of existence instead. Only the most experienced archmages could reduce this chance to zero. Regardless of its destination, the portal could not be moved or redirected once it was cast.

Components
Only verbal and somatic components were required to cast this spell and create a portal to a plane that the caster had previously visited. An object from a plane unfamiliar to the caster could be used as a material component to create a portal to that plane, in which case the object was not consumed by the casting but merely provided the link to that plane in place of the caster's memories.

History
This spell was found in a book that was known as "Elminster's traveling spellbook" although the Old Sage was not known to have claimed responsibility for the book or its peculiar habits. WorldWalk was later published in "Volo's Guide to All Things Magical" and became generally known to the magical community although it was uncommon to find it.