Your knowledge of the planes and teleportation allows you to travel with more precision.
Benefit(s): When researching a plane to which you intend to plane shift, you can attempt a DC 25 Knowledge (planes) check as you cast the spell. If you succeed at the check, you’re able to more precisely target your planar transport, allowing you to arrive 5d20 miles away from your intended destination instead of 5d% miles away. If you exceed the DC by 10 or more, you arrive 5d10 miles away instead, and if you exceed the DC by 20 or more, you arrive 5d6 miles away.
Pathfinder Roleplaying Game Ultimate Intrigue © 2016, Paizo Inc.; Authors: Jesse Benner, John Bennett, Logan Bonner, Robert Brookes, Jason Bulmahn, Ross Byers, Robert N. Emerson, Amanda Hamon Kunz, Steven Helt, Thurston Hillman, Tim Hitchcock, Mikko Kallio, Rob McCreary, Jason Nelson, Tom Phillips, Stephen Radney-MacFarland, Thomas M. Reid, Alexander Riggs, David N. Ross, David Schwartz, Mark Seifter, Linda Zayas-Palmer.