3e SRD:Mounted Archery
From D&D Wiki
|This material is published under the OGL|
Mounted Archery [General]
Prerequisite: Ride skill, Mounted Combat.
Benefit: The penalty the character suffers when using a ranged weapon from horseback is halved: -2 instead of -4 if the character's mount is taking a double move, and -4 instead of -8 if the character's mount is running.