Player's Handbook[]
A character with this proficiency has an innate sense of direction. By concentrating for 1d6 rounds, the character can try to determine the direction the party is headed. If the check fails but is less than 20, the character errs by 90 degrees. If a 20 is rolled, the direction chosen is exactly opposite the true heading. (The DM rolls the check.)
Furthermore, when traveling in the wilderness, a character with direction sense has the chance of becoming lost reduced by 5%.
The Complete Book of Dwarves[]
Dwarves receive a +2 bonus to their modifier when using their direction sense underground. They may use it above ground, but at a -2 penalty to Wisdom. Sundered dwarves should reverse these modifiers to reflect their fear of the underground.
Campaign Option: Council of Wyrms Setting[]
This proficiency gives a dragon that concentrates for 1 d6 rounds a chance to determine its direction of travel. Failure means the dragon is 90 degrees off the mark. A roll of 20 means the dragon is 180 degrees off. Success reduces the chance of getting lost during overland travel by 5%.
For dragons, this proficiency only works for land travel. For air or sea travel, dragons use the Navigation proficiency.
Hatchlings can take this proficiency.