One mount. TWO riders. In combat. How does it work?

[SinsI]

If two people are riding the same horse/dragon, what happens to their actions and initiative order? What if one of them does a (mounted) charge - can the other one attack, too?

[JDL]

From the SRD:

http://www.d20srd.org/srd/combat/specialAttacks.htm#mountedCombat

Your mount acts on your initiative count as you direct it. You move at its speed, but the mount uses its action to move.

A mount always acts on the rider's initiative order, performing their move action and/or standard action on that turn. If multiple riders are on the mount, only the first rider to direct the mount to perform an action will be able to direct the mount. Additional riders cannot make Ride checks to force the mount to perform any actions if it's already used its actions in that round.

[Dr_S]

I'm not sure where it would be in the rules, so I'll propose how I'd rule it if I were running a game. With 2 riders, I'd assume that one is "driving" and that you'd treat that player as mounted like normal.

The second rider would act on his own initiative, and would not have control over the movement of the beast but would not be using his move action unless he's drawing a weapon, dismounting or other move equivalent actions. If the rider wants to strike during a charge or some other coordinated action, he has to be coordinating with the driver, so to attack on a charge, on his turn he'd have to ready the action for "when the driver charges"

If they are not allies or are having a disagreement and one decides to wrest control of the beast from the other, I'd call that an opposed ride check perhaps with a minimum to not risk getting knocked from the mount. (In pathfinder I'd use CMB V CMD with ride checks not to get booted off the animal entirely) The mount would respond to commands on the player's next initiative (if control is retaken by the previous driver, they don't get control until their next turn, and the mount acts without guidance for a round... this creates a scenario where 2 people wrestling for control can actually legitimately run off a cliff)

[Dr_S]

only the first rider to direct the mount to perform an action will be able to direct the mount.
This interpretation allows for the rider in back to direct the mount, though (s)he would not have control of it, simply by winning initiative.

[JDL]

This interpretation allows for the rider in back to direct the mount, though (s)he would not have control of it, simply by winning initiative.

Correct. By RAW there is no front or back of the mount. A rider shares all squares of his mount's space at all times. This would include situations where two riders are sharing one mount as well.

[Urpriest]

Going to echo others. One of the "riders" is actually a passenger, they aren't both riders.

[Bronk]

I think the passenger would be limited to 'Stay In Saddle' checks, and probably a lot of them in a combat situation.