My friends and I have always felt that spellcasters had far too many advantages, especially at high levels against warrior types. We made a few house rules, but even still warriors were in effect still inferior. So we came up with the following rules. This could potentially level the playing field, probably up to around level 15 or so, but hey progress is progress.

These rules assume the following:
Immediate and Swift actions are two seperate actions. So if you use an Immediate action in one round you dont lose your swift action in the next. You are granted one of each per turn.

Dynamics of Combat

Parry
Once per round as an immediate action a character can make an opposed attack roll to negate a single ranged or melee attack that would otherwise strike him or an ally within his reach, or if using a ranged weapon within range of the weapon. You make an opposed attack roll that if it is greater than your opponents attack roll, their attack is negated as though it failed to overcome your Armor Class. The character may only declare a Parry before knowing the result of the opposed attack roll.

Whenever a character makes full-attack action you may choose to reserve any number of attacks to make additional parry's in a round equal to the number of attacks reserved. Regardless of how many attacks a character reserves. Even after the initial immediate action is used a character can continue making subsequent parry's at any time during the round. All parry attack rolls are subject to the same bonuses and penalties as a standard ranged attack roll, including the usual penalty to iterative attacks. A character cannot parry if they are caught flat-footed or is denied his dexterity bonus to AC.

Parrying with Shields
A character may choose to parry with a shield as he would for any weapon, however you add the Shield's AC bonus on all parry attempts you make. You do not lose the benefits of the Shields AC bonus as you normally would for making attack while using it in this fashion nor do you apply its armor check penalty to your attack roll.

Movement
During your turn you may make a full-attack action and still move up to your speed. The character is subject to attacks of opportunity while doing so, but may tumble normally as part of his move. If you are prevented from completing your move you are also prevented from finishing your full-attack action. You must move a make a minimum of 5 feet of movement between each attacks. For every 10ft of movement covered during your full-attack action you suffer a cumulative -2 penalty to all attack rolls and movement related skills such as Jump or Tumble until the start of your next turn.

Evasion and Area of Effects
When using an Area of Effect spell, ability or power, it does not come into effect until the start of your next round. You must designate the area when you cast or use the ability. For example if you cast the spell Fireball, you must designate its area during its casting.

Characters aware of an immenient attack are free to move out of the area or prepare some means of defense. In the event a character is in the area of effect and was unable to get out of the area or were unaware of an area of effect targeting his or her area, they are entitled to a reflex save. If successful they are able to as an immediate action use a move action to move at one-half their speed. If a character is unable to find cover they still suffer full damage from the effect. A character who chooses to move in this fashion is in effect giving up their move action the following turn.

Characters with the extraordinary ability Evasion gain a +4 bonus on their Reflex save and if successful may instead move up to their full movement speed. Those with Improved Evasion instead gain a +8 bonus on their reflex save count as though they had cover if they are able to move at least 20ft from the area of effect.

Just like the Parry mechanic a character may choose to reserve movement on their turn to allow them to move within the next round using an immediate action, similar to a parry. Instead of an attack roll you roll a Tumble check with a -5 penalty with the attack roll set as the DC. Each subsequent attempt incurs a cumulative -5 penalty to your check and each 10ft of movement reserved allows you to move up to 5ft. Even after the initial immediate action is used a character can continue to move at any time during the round.

Cover and Area of Effects
If a character has cover, they only suffer 1/2 the damage from an area of effect, regardless of their position unless its effect was a spread (which can extend around corners and thus negate this cover bonus). Characters with full cover suffer no damage from an area of effect unless said effect was a spread.

Shields and Cover
A shield can be readied to grant cover against an Area of Effect. You may only ready shields of an equivalent size to your own gain the benefits of cover against an area of effect. For example a medium sized creature wielding a large shield who used the readied action would have cover against an area of effect. Shields that are larger than its owner grant full cover against an area of effect.

In addition if you are wielding a Shield and are forced to make a reflex save against an Area of Effect, you may instead of moving protect yourself with your Shield. Because of how quickly you must adjust your shield you only manage to block some of the damage, suffering only 3/4 of the total damage (as opposed to 1/2). You are still considered to have expended your move action the following round by using this maneuver.

Questions, comments?