The edge, and other combat-system changes:
* Note that if two combatants have equal BABs, neither has the edge.
* Sizing up an opponent: When using the Sense Motive skill to estimate the relative combatworthiness of an opponent (compared to yourself), success will also allow you to determine whether you have the edge on that opponent.
* Feats which give a numerical bonus to attacks, damage, AC, or saves instead give a bonus of (listed bonus)+(hit dice)/5 rounded down.
* For every additional attack granted by having a high BAB, the penalty to hit is a flat -5.
* If you have a high enough BAB to get additional attacks, you also get additional attacks of opportunity. Use the same progression as ordinary iterative attacks.
* The Combat Reflexes feat stacks with iterative attacks of opportunity. It grants additional attacks of opportunity equal to your Dex bonus, at your full BAB, and allows you to make AoOs in any condition where you are not prone (unless you have the Prone Attack feat) or helpless. (So joining a grapple on someone with Combat Reflexes provokes an AoO.)
* The Improved Two-Weapon Fighting feat grants a set of additional off-hand attacks based on your BAB. (Yes, this means a high-level fighter who's taken the TWF track gets to stab people as often as 8 times during an ordinary round of combat. (12+Dex) times with Combat Reflexes, if their opponent(s) actually give them all possible chances at an attack of opportunity. If a combatant is dumb enough to let themself be flanked by a 15th-level-or-higher rogue who uses TWF, they'll be taking as many as six sneak attacks, with 8d6 to 10d6 extra damage dice, each. You roll (6d6 or 8d6)x4 for a Meteor Swarm, too, so the monsters are already scaled for that kind of thing.)
* Combat Expertise and Power Attack cease to be feats. (Feats with Combat Expertise & Power Attack as a prerequisite are otherwise unchanged.) Instead, they're general melee options as described below:
-- Expertise: (Prerequisite: BAB +1, Int 13) Before making any attacks during your turn, you may take an attack penalty of up to your BAB on all attacks until your next turn, and gain an equal Dodge Bonus to AC. You may only use this option once per turn.
** A combatant with the edge may choose to fight defensively at the same time, at the same rate of exchange.
-- Power Attack: (Prerequisite: BAB +1, Str 13) Before making any attacks during your turn, you may voluntarily take an attack penalty of up to your BAB, and inflict that amount in extra damage with that attack. The bonus and penalty apply to all of your attacks, until your next turn.
** A combatant with the edge inflicts 2x the amount of their attack penalty in extra damage.
The Edge and Combat Maneuvers
The edge represents a creatures' greater skill in combat. Combat maneuvers just plain work better when one has the edge.
* Bull-rushing: Pushing an opponent backwards is done by moving into their square (which often provokes an attack of opportunity), then make an opposed strength check of (1d20 + Str + Size modifier) against the creature being rushed. (The attacker gains an additional +2 if charging.) Failure pushes the attacker into a random adjacent square. Success pushes the opponent one 5' square away from the attacker, along the line of their movement. A combatant who succeeds by two or more may move with their opponent to force them backwards one square for every two points by which the attackers' check results exceed the defenders'. During a bull-rush, both opponents provide cover for one another.
** An attacker with the edge during a successful bull-rush may push their opponent up to 45 degrees off the line of the rush. The attacker recieves, but does not provide, cover during this movement. If an attacker with the edge fails their initial strength check, they may choose which square they rebound into.
* The Improved Bull-Rush feat operates as normal.
* Coup-de-Grace: This is an attempt to slay a helpless opponent. It requires a full-round action, and is an automatically confirmed critical hit. A rogue's sneak attack damage is also added to a CdG. If the opponent survives the damage, they must make a fortitude save (DC 10 + damage taken) or die from shock. Coup-de-Grace's provoke attacks of opportunity.
-- Interruption: A creature that suffers damage during a CdG must make a Concentration Check (DC 10 + Damage Inflicted) or the action is resolved as a normal attack.
** An attacker who has the edge on an opponent who threatens them during a Coup de Grace does not provoke an attack of opportunity from that opponent.
* Covering Fire: Ranged attacks may be used to provide cover for ones' allies. Take an attack with a creatures' ranged weapon and roll a normal attack roll (with the -4 penalty for firing into melee). Until the beginning of their next turn, one of their allies may use the result of the attack roll as their armor class against one attack of opportunity.
** A combatant with the edge against an opponent whose attack of opportunity was negated by Covering Fire may hit the opponent with it. Simply compare the attack roll to the opponents' armor class as if it was also a normal attack.
* Disarm: A combatant may attempt to disarm their opponent with a melee attack. To attempt to disarm an opponent, make an attack roll against an "armor class" of (10 + the target's melee attack bonuses) with the item in question. (If attempting to "disarm" someone of an object which is not a melee weapon, it's an improvised weapon. Most defending creatures will take a -4 nonproficiency penalty.) Success means that one weapon or held item is knocked out of your opponent's grasp. Failing a disarm attempt provokes an attack of opportunity from the target. A disarmed item lands in a randomly determined square adjacent to the target.
-- Defending against a Disarm: An item held in two hands is harder to disarm, increasing the DC by +4. An item attached to one's body with a sword-wrap or locked gauntlet is much harder to disarm, increasing the DC by +8.
-- Special: As an attack of opportunity or a readied action, a combatant may attempt to remove a melee weapon that is presently being used in an attack against them, even if the opponent using the weapon is out of range or otherwise not threatened by the combatant. (This means that if you're sufficiently prepared, you can try to disarm a longspear while someone's trying to stab you with it.)
** A combatant who has the edge on their target does not provoke an attack of opportunity when a disarm attempt fails. If they succeed, they may choose which adjacent square their opponent's weapon or held item lands in. If the disarmer has a free hand, the item may end up in their possession instead.
* The Improved Disarm feat grants a +4 bonus on the opposed attack roll to disarm an opponent. A creature with Improved Disarm does not provoke an attack of opportunity during disarm attempts, even if they are unarmed/fail their disarm attempt/do not have the edge. A failed disarm attempt against a creature with Improved Disarm grants the creature a free attempt to disarm the attacker. (Two creatures with Improved Disarm who both fail their disarm attempts do not get further reactive attempts to disarm one another.)
* Feinting: Feinting in combat is a standard action for creatures with Dex 14 or less, and a move action for creatures with Dex 15 or higher. You make a Bluff check (with your BAB as a circumstance bonus), opposed by your opponents' Sense Motive check (with their BAB as a circumsntance bonus). Success will deny your opponent their Dex bonus to AC on the next attack you make against them within one round.
** A combatant who has the edge and successfully feints may immediately make an attack against their opponent, as a swift action.
* The Improved Feint feat improves feinting as usual for creatures with a Dex score less than 15. Creatures with a Dex score of 15 or greater who take Improved Feint may instead feint as a swift action, and when such a creature successfully feints with the edge, the extra attack is considered part of the same swift action as the feint.
* Tripping: As an attack action, you may attempt to knock an opponent prone.
-- Without a weapon: Make a touch attack, which provokes an attack of opportunity. If you succeed (regardless of the AoO results) make a Strength check (+BAB) opposed by the other combatants' Str or Dex (+BAB), whichever is greater. Success leaves your opponent prone. Failure grants your opponent a free trip attempt against you.
-- With a weapon: Attempting to trip with a spiked chain, any variety of flail, guisarme, halberd, whip, spiked gauntlet/boot, or with an appropriate natural weapon, is considered an armed attack. Failing an armed trip attempt provokes an AoO.
Modifiers: Creatures with four or more legs, or which are otherwise inherently stable, gain a +4 bonus to avoid being tripped. Radially symmetrical creatures like Oozes cannot be tripped at all.
** If you have the edge on your target during a failed trip attempt, failure does not grant a trip attempt or AoO. If your trip attempt succeeds, the target immediately provokes an AoO from you.
* The Improved Trip feat allows one to make an unarmed trip attempt without provoking an attack of opportunity, and grants a +4 bonus on the opposed check to trip an opponent. Tripping an opponent grants an extra melee attack at the same BAB used in the trip attempt, in addition to any AoO gained from having the edge in this situation.
* Grappling: The current grappling rules are confusing; consider this an attempt to simplify them. Grappling consists of:
-- Grabbing on: To grab another combatant, make a touch attack that provokes an attack of opportunity. The attack must succeed against the opponents' touch AC + their BAB/2. If you succeed, you automatically move into your opponents' square.
[If the grapple initiator takes damage from the attack of opportunity, it doesn't necessarily foil the grab attempt. Ex: fighter A attempts to initiate a grapple with monk B. B's AoO succeeds, and B kicks A. A's touch attack also succeeds, leaving A holding B's leg. They are now considered to be grappling.]
** A combatant who has the edge when attempting to grab another creature does not provoke an attack of opportunity.
-- Being held/Holding on: Grappling combatants lose their Dex bonus to AC against opponents who are not engaged in the grapple. They threaten no squares, and may not make attacks of opportunity.
--- A combatant who's being held must succeed on an opposed grapple check (1d20+BAB+Str+size modifier) in order to take any move or standard action, with the exception of casting spells that lack somatic and material components. A combatant being held may attack beings who are part of the grapple with a light or natural weapon, but their Str bonus is halved and the attack is made with a -4 penalty. Escaping a grapple requires either a grapple check or an Escape Artist check with ones' BAB as a circumstance bonus, opposed by the other combatants' grapple check(s).
** If a grappler with the edge is being held, their attacks do not have a penalty.
--- A combatant who's holding onto an opponent may attack that opponent with a one-handed, light, or natural weapon, without penalty. The combatant must use at least one hand to maintain the grapple, and is unable to attack with that hand (sorry, no TWF here). If (and only if) the grappler is two or more size categories larger than the combatant being held, they may attack creatures outside of the grapple, at a -4 penalty.
** If a combatant with the edge is holding onto another creature, they may prevent that creature from attacking anyone.
-- Pinning: A grappler may attempt to pin the opponent they're holding for one round, by making an opposed grapple check. Use of an available surface gives the grappler +2 bonus. If the floor is used, the combatant being pinned becomes prone (if they weren't already), and takes the usual penalty. The combatant being pinned is considered helpless, and may be prevented from speaking, at their opponents' option. A pin can be broken in the same way as a grapple, and returns the combatants to their grappling state.
** A combatant with the edge can attack an opponent they're pinning.
* The Improved Grapple feat operates as usual.
Miscellaneous other little things:
* Gaining proficiency with a weapon does not take a feat.
-- Any creature with martial weapons' proficiency who spends a week practicing with a weapon with which they are not proficient may make a DC15 Intelligence check to gain proficiency. If the week is spent practicing with someone who already has proficiency, the DC is reduced to 11. (And no, you can't take 10 on that.) A creature who fails at this, but keeps practicing for an entire level, automatically gains proficiency the next time they gain a level.
-- Any creature that doesn't have martial weapons proficiency, but practices regularly with a weapon for an entire level, automatically gains proficency with that type of weapon the next time they gain a level.
Questions, comments, and suggestions appreciated.