rules for closing a portal

[hwkies]

i am planning on introducing some portals to different choatic planes into my game...caused by the main bad-guy in our campaign. i cannot find any rules for closing of magical portals to other planes. I am sure there are specific rituals for this, but i can't seem to locate the spells or rituals descriptions.

any help with location of these rules would be awesome!
thanks in advance.

[Robot_nachos]

Well, Dispell magic (and a certain awesome barbarian rage power) is one of the only things that would work by RAW (I'm assuming that the portals are spells and not supernatural effects) barring that, the GM really has to make something up.

[Drejk]

If the portal is a spell, then dispel magic. Possibly dismissal/banishment depending upon the exact specifics of the portal. If it is permanent magic item then disjunction.

Otherwise, the portals should be closed/destroyed through plot device methods, because portals are plot devices themselves.