How does mounted combat work in pathfinder?

[Kallimakus]

I've been confused by this for a while now because I haven't been able to find a quick and simple breakdown of the actions involved.

I also have some specific questions that were used against me in a PVP situation.

1) Can a rider use his quick runner's shirt to make his mount take an additional move action?


Quick runner's shirt
Once per day as a swift action, the wearer can take an additional move action to move on his turn.

2)In order to use ride-by attack, do you need to be more than 2 squares away. My enemy used ride-by attack after attacking me with his lance on the previous turn.

3) Lance and spirited charge. Is the full damage multiplied, or just the damage die of the weapon.


Lance
Benefit: A lance deals double damage when used from the back of a charging mount. While mounted, you can wield a lance with one hand.

Spirited Charge
Benefit: When mounted and using the charge action, you deal double damage with a melee weapon (or triple damage with a lance).


4) Quick dismount. If I fail the check, does the mount also lose a move action, preventing the use of Full attack, or just the rider, who has to take a move action to disembark.

Bonus question: Does quick runner's shirt stack with haste spell? Also, I'm not sure how they played it, but mount is a separate entity and thus a separate creature from the rider. If the rider has haste, a horse still only moves 50 feet, correct? The enemy group had a 5-man party and a level 5 wizard casting haste. Does haste allow use of Quick runner's shirt, which has haste as a craft requirement?
(FAQ states that Lead blades and Impact magic weapon property don't stack, haste says it doesn't stack with haste.)

[gartius]

1) yes as he can use the move to direct the horse.
2)was he two squares away from you before rideby attacking? if not then he shouldn't have been able
3)the full damage is multiplied.
4)is the mount battle trained? if not then it cant act as you have to direct it to attack. If it is then it gets its own full actions.
5) if rider has haste then the horse doesnt gain the bonus speed-but what stops the wizard excluding himself from the haste and casting it so that the horse gets the effect instead?
6)quick runners shirt does stack as it is two separate abilities. (swift for a move compared to extra movement per turn) compared to a spell and an item that does the same ability. (increases damage dice)

[Ssalarn]

I've been confused by this for a while now because I haven't been able to find a quick and simple breakdown of the actions involved.

I also have some specific questions that were used against me in a PVP situation.

1) Can a rider use his quick runner's shirt to make his mount take an additional move action?


2)In order to use ride-by attack, do you need to be more than 2 squares away. My enemy used ride-by attack after attacking me with his lance on the previous turn.

3) Lance and spirited charge. Is the full damage multiplied, or just the damage die of the weapon.


4) Quick dismount. If I fail the check, does the mount also lose a move action, preventing the use of Full attack, or just the rider, who has to take a move action to disembark.

Bonus question: Does quick runner's shirt stack with haste spell? Also, I'm not sure how they played it, but mount is a separate entity and thus a separate creature from the rider. If the rider has haste, a horse still only moves 50 feet, correct? The enemy group had a 5-man party and a level 5 wizard casting haste. Does haste allow use of Quick runner's shirt, which has haste as a craft requirement?
(FAQ states that Lead blades and Impact magic weapon property don't stack, haste says it doesn't stack with haste.)

1) No. The mount uses its own action to move. Gartius is mistaken. From the CRB (http://paizo.com/pathfinderRPG/prd/combat.html#mounted-combat): "Your mount acts on your initiative count as you direct it. You move at its speed, but the mount uses its action to move."

2) Ride-by Attack is useable with a mounted charge, which requires both the mount and rider to use the charge action (http://paizo.com/paizo/faq/v5748nruor1fm#v5748eaic9ru6[/url). If they didn't have 10 feet of room as required to start a charge, it wasn't a legal attack.

3) You multiply everything except precision damage and extra bonus dice (such as from the flaming property. Strength bonuses, weapon damage die, Power Attack bonuses, enhancement bonuses and most other static bonuses are multiplied.

4) Ride checks are generally rider specific. The rider loses the action, not the mount.

Bonus) Since the quick runner's shirt does not, strictly speaking, grant an effect similar to haste, they technically stack, but given that haste is the component spell to craft a quick runner's shirt, there's a fair argument either way, and precedence set by other properties that use haste as a base not stacking would indicate that if there were an official ruling, they probably wouldn't stack.