The outer planes are associated strongly with the beliefs and alignments of the Prime. As a result these planes may have a significant effect on those whose alignments do not match that of the plane. These affects stack should a character fall under more than one affect.

Mildly aligned: Those of opposing alignment are at a -2 to Cha checks.
Strongly aligned: Those not of this alignment are at a -2 to Cha, Int, Wis checks