MarkB
Legend
Just checked on Exodus Knife:
Exodus KnifeLevel 12 Uncommon
This insubstantial silver blade appears to cut through solid walls.
Wondrous Item 13,000 gp
Power Daily (Standard Action)
When you use the exodus knife to trace a doorway onto a solid object, it opens a portal into an empty extradimensional space 4 squares wide, 4 squares high, and 4 squares long.
While the door is open, anyone can enter, see into, or affect the extradimensional space. Only creatures inside the space can open or close the door (a minor action). Once closed, the door becomes invisible to anyone outside the extradimensional space. Creatures on the inside of the closed door can see out, but those outside can't see in. Creatures on one side of the closed door cannot affect creatures on the other side.
The extradimensional space lasts for 8 hours. Any creatures still in the space when the effect ends reappear in the closest unoccupied squares outside the door.
Heh, that's a long way from 3e's universally available, 2nd level Rope Trick spell!
Not entirely. As an item, it doesn't tie up any spell slots and isn't particularly expensive at Paragon levels - and, of course, anyone can use it. And 3e's Rope Trick only becomes viable as a resting area once you have a 9th-level caster, so that its duration exceeds an 8-hour rest.
Given the larger level range, 4e's 12th level is proportionally no higher than 3e's 9th level.
On the other hand, 4e's revised loot system does mean that it's now GM's prerogative as to whether the party obtain the knife, something I hadn't taken into account as I bought ours before we switched over to the rarity system.