Portal Reformat

(Underdark, p. 60)

Transmutation
Level: Portal (Alternative) 8,
Components: V, S, DF, XP,
Casting Time: 10 minutes
Range: Close (25 ft. + 5 ft./2 levels)
Target: One portal
Duration: Instantaneous
Saving Throw: None
Spell Resistance: No

A portal reformat spell permanently removes or adds one or more keys to a portal (see Portals in Chapter 2 of the FORGOTTEN REALMS Campaign Setting).
The caster must have studied the portal with the analyze portal spell (or some similar means) and must know its properties before he can add or remove any keys.
Removing a Key: Removing a key from a portal changes it from a portal activated only by that specific key to either a portal that cannot be activated at all or a portal that can be activated by any creature (caster's choice).
If the key controlled the behavior of the portal, the caster can decide which behavior to remove.
For example, in the case of a variable portal that leads to one destination if activated by a drow and another destination if activated by any other creature, the caster could remove either destination, making it a portal that sends any other creature to one destination or a drow to one destination.
Adding a Key: You can add a key to an existing portal to prevent it from being activated unless the creature attempting to activate it has the key.
If you designate a specific object or type of object as the key, you must have that object on hand for the casting of the spell.
You can also add a key that changes the behavior of a variable portal, if you so choose.
For example, if a variable portal formerly operated one way for drow and another way for all other creatures, you could add a key that is nearly impossible to obtain for the "all other creatures" function, effectively changing the portal into a drow-only portal.
XP Cost: 250 XP.