Magic portals link diverse places across the world and across the planes. A portal is an immovable magical surface of a size and shape created by its creator. The surface is often situated in a physical frame, such as an arch or doorway, that stands free rather than inside a wall. Some portals allow those looking at it to view the location where those who use it will arrive. A creature trained in Arcana can make a DC 24 Arcana check to detect a portal’s magic.

    Effect: When a creature passes through the surface of a portal, it is transported to a set destination. Putting any significant part of an object or body through the portal’s surface transports the whole object or creature to the destination, unless an obstacle blocks that space, in which case the portal doesn’t function. If a creature occupies the destination space, the creature being transported is shunted to the nearest unoccupied space. Any number of creatures can enter a portal at the same time, as long as the portal’s size can accommodate them.
    Unattended objects, such as a flying arrow, can’t pass through a portal by itself, instead bouncing off. There is no line of effect for powers and rituals to work through portals, unless the portal was designed that way.
    A portal’s creator can set extra limitations on a portal. One limitation is the requirement of a key to pass through a portal. Another limitation is restricted access, so that only specific creatures or objects can pass through.
    A portal can have multiple preset destinations, allowing the user to select among them, or based on the key used. Other portals will set the destination randomly.
    A portal can also malfunction. The most common malfunction is an unintended or random destination. Some malfunctioning portals have strange effects.
    Usage: A great way to change up an adventure from what is expected is to use a malfunctioning portal, just don’t introduce one too often or the players will avoid all portals, or examine each one to make sure it’s safe. If the group believes they are going to one location and prepare for that destination, send them to another completely different location they aren’t prepared for (for example, if they are prepared to go to the Hells, send them to an icy world in the Astral Sea. Give them a way back, however, if you don’t want the story to change course for an extended period.

Published in Forgotten Realms Campaign Guide, page(s) 54.