Mounted Combat stuff
From Sidewinder, Mounted Combat, pg. 224:
Controlling A Mount : The steps necessary to control a mount in combat differ depending on whether the mount is trained for combat (see Handle Animal skill).
Trained Mounts : Directing a trained mount to move or perform any other action in combat requires a move action by the rider. If the mount doesn't act or move (other than a 5-foot step) the rider doesn't need to spend an action. The move action may occur before or after the rider's remaining move or attack action. A Ride skill check isn't required to control a trained mount.
Untrained Mounts : For mounts that are easily frightened and haven't been trained to tolerate the noise and chaos of battle, a Ride check is required at the beginning of any round. The DC of this skill check is 20. (See Ride skill for modifiers and complications to this skill check). If the skill check succeeds, the rider spends only a move action controlling the mount. If the check fails, the rider must spend the entire round controlling the panicked mount and no other actions are possible until the next round.
Mounts in Combat : The mount moves and acts on the rider's initiative count as directed by the rider. As with any creature, the mount is able to take a move and an attack action, two move actions, or a full-round action. All of the mount's actions are resolved during the controlling action perfomred by the rider.
Combat While Mounted : With a DC 5 Ride check, a rider can guide the mount with his or her knees so as to use both hands to attack or defend. This is a free action.
Melee Attacks : If the mount charges, both the rider and mount suffer a -2 penalty to their Defense. If either the rider or the mount makes a melee attack at the end of the charge, a +2 bonus to the attack roll is gained. In all respects, the rider is considered as charging. If the mount runs, withdraws, or makes a double-move, the rider isn't allowed to perform a melee attack either before or after the mount moves. The mount spends the entire round moving and there is insufficient time for the rider to make a melee attack.
Ranged Attacks : When firing a longarm from the back of a mount, a character suffers a -2 penalty to all attack rolls unless the longarm is a carbine. Attacking with a ranged weapon while mounted results in penalties for attacking from a moving platform (see Attack Roll Modifiers, pg. 215). If the mount makes only a single move action, the character doesn't suffer a penalty because the motion is gentle enough to attack normally. If the mount moves twice, withdraws, or charges, all ranged attacks are made at a -4 penalty. If the mount runs, the penalty is -8. These penalties can be reduced by possessing either the Blazing Saddles feat or the Cavalry Training feat.
Withdraw : As usual, if the mount withdraws it doesn't provoke attacks of opportunity for moving from its initial square. The rider, however, will provoke attacks of opportunity for moving unless the only actions the rider takes during the round are move actions.
Riding Defensively : A rider can direct his mount to move in such a way as to make both the rider and mount difficult to hit in combat. Each gains a +2 dodge bonus to Defense at the expense of the mount and rider suffering a -4 to all attack rolls. Additional passengers receive the same bonus and penalty as the rider.
Total Defense : A rider can completely abandon all possibility of attack to gain a large bonus to Defense. By surfeiting all attacks by rider and mount during a round, both gain a +4 dodge bonus to Defense. Addional passengers receive a -8 penalty on attack rolls. These modifiers last until the rider's next round of actions. Total defense requires an attack action from both the rider and the mount.
Full Attack Action : A rider cannot normally make a full attack, because controlling the mount requires a move action; however, passengers can take full-attack actions, because they don't have to use a move action to direct the mount. There is one exception to this rule prohibiting riders from taking full attack actions. Characters with at least two levels in the Pony Soldier advanced class only need to spend a free action to control a trained mount. This free action can be taken before or after all other actions in the round. Even though a Pony Soldier is able to control his or her mount and make a full attack in the same round, he or she cannot make melee attacks if the mount runs, withdraws, or performs a double move. This restriction doesn't apply to ranged attacks. Furthermore, as usual, the Pony Soldier is unable to make more than one melee attack after a charge.
If a Mount Falls in Battle : If a rider's mount falls, the rider must succeed on a DC 15 Ride check to make a soft fall and suffer no damage. If the check fails, and the mount's last movement consisted of a single move or remaining stationary, the rider takes 1d6 points of damage. If the mount's last move was two move actions, the rider takes 2d6 damage. If the movement was a run, the damage is 3d6.
If a Rider is Dropped : If a rider is knocked unconscious, he or she has a 50% chance to stay in the saddle. Otherwise the character falls and takes the same damage as if the mount was killed or knocked unconscious. Without anyone to guide it, the mount normally avoids combat, unless the mount has been trained in the Guard trick.
Being Struck while Mounted : Any rider that takes damage from an attack must succeed on a DC 5 Ride check or be knocked off of the mount. A rider that falls must succeed at a subsequent DC 15 Ride check or take damage (1d6, 2d6 or 3d6, as above). When an opponent attempts to trip a rider, instead of making a Dexterity or Strength check to avoid the trip, the rider may oppose the trip attempt with a Ride check. If the trip attack succeeds, the rider is unhorsed and falls prone to the ground, taking damage appropriate to the mounts movement.
Being Dragged Behind a Mount : As with the classic staple of lynch mobs throughout time, when a character is attached to a mount by a rope or chain and is dragged along the ground, he or she takes damage each round according to the mount's speed and the terrain. (Damage as per movement above). If the ground is relatively smooth and slippery (a dusty road for example) the damage is halved. If the ground is rocky, sharp, or rough, or heavy with brush, the damage is doubled. Each round a character is allowed to make a DC 15 Reflex save. If the save succeeds, only one-half damage is taken.