Plunging Shot

(Races of the Wild, page 152, DnD 3.5)

[General]

You can use the force of gravity to make your ranged attacks deal extra damage if your target is below you.

Prerequisite

Point Blank Shot, DEX 13

Benefit

If your target is at least 30 feet lower than you, you deal an extra 1d6 points of damage with a thrown or projectile weapon.