[gurps] Portals

[All Hail Discordia]

Chris wrote:
> Heres hoping someone can give me a bit of clarification, an answer or at least a plausible reason.
> I am currently running a fantasy game and have had the party of delvers find an underground circular room that gives a lovely panoramic view of the world outside above ground, just beyond this informational illusion is a wall with corridors leading off at cardinal points.
> What one sneaky delver is currently seeing in the panorama from a hidden vantage point is a Lich pointing an amulet into the room from outside allowing his minions to enter the room to head to the barracks.
> This amulet only works one way, allowing the lich to point the way for his minions to go ahead of him to ensure his safety.
> What one of the players wants to do is use apportation from inside the room to snatch the amulet from the Lich who is outside.
> Technically, the Lich is actually about 1,000 yards higher and a good 2 miles further north.  From the delvers point of view, the Lich is about 7 yards away.
> Q1. Would apportation work the wrong way through a one way portal.
> Q2. What range penalties should I be using.

A one way portal is one way. If mass and light can only flow one way 
then "logicaly" magic or psionic energy's can only flow one way too. In 
fact the Lich and his minions would not be able to see their destination 
at all, they would be looking at a blank wall or and empty space. For 
them to see the destination light at the very least has to pass back to 
them.

So your answer to Q1 is no and that makes Q2 irrelevant. That said, many 
  psionic abilities were given a fuzzy line of sight rule i.e. through a 
TV or other remote viewing device. If you want to do the same with Magic 
use the standard long distance modifiers.

[snip]