Riding
Defaults: DX-5 or Animal Handling (same)-3.
This is the ability to ride a particular kind of mount. Make a skill roll when you first try to mount a riding animal, and again each time something happens to frighten or challenge the creature (e.g., a jump).
You must specialize by riding beast. Defaults between specialties vary from 0 to -10. For instance, if you have Riding (Horse), Riding (Mule) is essentially the same skill (no default penalty), Riding (Camel) would default at -3, Riding (Dolphin) at -6, and Riding (Dragon) at a whopping -10!
Modifiers: +5 if the animal knows and likes you; +1 or more for a mount with the Mount skill; -10 if the animal has not been trained for riding.