How to prevent planar travel to your world.

[Cespinar]

The BBEG in my game is probably going to exile the characters to the planes since killing them could easily prompt a resurrection and they know something very sensitive to his plans. Besides just banning all forms of planar travel spells and not letting them find portals back is there an easier way to prevent them from coming back till I want them too? Is an artifact the best way to go?

Before he banishes them the major arcane guild I have in my world is a group of Conjurers that perform extra planar experiments when summoning so it can't be something that has always been there just something he could do to get this effect.

The main problem was I was going to run a few adventures that originate in Sigil. Having them not find a portal could be easy As the BBEG rendering all the protals on the world useless. But ones they get spell like planeshifting I don't want them to simply planeshift back or even hire someone to do it for them. I would rather they have to do a quest at a higher level to make it back home.

 

[Suldulin]

a) make the world a demiplane? works for ravenloft
b) epic level spell, ala darksun 'canon'
c) maybe a highpower curse on the pc's?

 

[DM with a vengence]

The BBEG has put a trap on the astral link into the thier home plane. When it detects them coming in, they get shunted to a unfriendly location of your choice, or possibly just wind up dumped in the Deep Astral.

 

[The Goblin King]

Somehow the BBEG has created a huge Planar Rip around the planet. The material plane is entirely cut off from all transitive planes. Plane Shift, Etheralness, and Shadow Walk do not work.

 

[Crothian]

Just have it impossible and no one seems to know the real reason. Some mysteries do not have answers.

 

[Viktyr Gehrig]

Sovereign Glue and shackles with Dimensional Anchor enchanted.

 

[s/LaSH]

There's always the plan of throwing them into some weird and distant corner of the multiverse, corresponding to nowhere the PCs are familiar with. Say that spells like Plane Shift are simply 'out of range' if they want to return to their home world (because where they're standing is parallel to hard vacuum). Then it becomes a quest to find portals leading to a more familiar region of the multiverse. A vast, huge range distance should be capable of defeating even Teleport, if they find their way back to another Prime Material world...

 

[Angcuru]

Put them in a poorly-designed warehouse-style hardware store.

 

[Angcuru]

Hey Cespinar, would you like to make me "Shiny Ones"? Y'see i got these two parts to a legendary weapon......

 

[Lord Pendragon]

Do you have access to the Manual of the Planes? If you do, solving this problem is relatively easy. Simply create a demi-plane with the Limited Magic attribute. Such planes only allow certain schools of magic to function, any other spell simply dies, as if the spell were cast in a dead magic zone (anti-magic field).

Since Planeshift is from the Transmutation school, simply disallow Transmutation. This leaves only Color Pools, portals, and the 9th-level Gate as means of leaving the demi-plane. This would also make things interesting, because losing Transmutation means losing a number of buffing spells as well. The party may have to change strategies.

Another way would be to give a demi-plane the Impeded Magic trait, which forces spellcasters to make a Spellcraft check in order to cast spells from certain schools, but that means there's still a chance the spell will succeed.