Discern Portal Destination (3.5e Spell)

You probe the portal, finding its destination

You instantly know the destination of the target portal. If the portal leads to another plane, it tells you which other plane it leads to, although it tells you nothing about the plane in question if it's one you've never heard of. If the portal leads to the same plane, it tells you the general direction (to within about 10 degrees) and distance, plus or minus 20%. You also know if the portal is one-way or two-way.

If the portal has multiple destinations, it reveals the one it would take you to were you to step into it. If something has just gone through the portal (within the last two combat rounds) or if the portal would not work for you for whatever reason, it tells you where the last thing to go through got taken. If it's random, it reveals one randomly-selected destination, which is not necessarily where it will take you when you step into it. For most portals, this spell examines them without disturbing them, although very sensitive portals may make a will save to be disturbed by it. On a successful save, those portals behave as if something went through the portal in response to the spell, changing destinations or setting off alarms appropriately. The spell doesn't actually reveal any of these traits of the portal.