During the last session of my d20 Modern game, I had a player and NPC on horseback, and I realized that the rules aren't clear on the Action breakdown between horse and rider.
Ride Animal doesn't state whether or not controlling the animal takes an Action, just that you can do all sorts of reactionary stunts to keep your hands free or take cover. And it also doesn't say whether or not the horse's movement is tied to the horse's actions or not.
So, in short, how does this work? Does the horse decide "I'm using a Full Action to move x4 my base movement", and the rider gets their standard Move Action and Attack Action, or does the rider have to use a Move action to control the horse? Does the rider have to use a Full Action to get the horse to do an all-out move?
Related: the chase/driving rules do state that controlling a vehicle is a Move action. I chose to do that to keep the game moving at the time, but I'd like to know the "real" answer. IE, Rules as Written, if there is one.