Yeah, no way I'll finish writing this up before midnight. This post repeats some previously mentioned material in an attempt to lay out all the various relevant ideas I have; part 2 will discuss how all these individual changes interact with one another to fundamentally alter how the combat works, at least in theory. The hoped-for end result is that the revisions will simplify (and thus speed up) combat while simultaneously making it less abstract. In other words, I'm trying to have my cake and eat it too.
-Saga Edition-style reflex defense. I've discarded the "Guard Defense" mentioned in the "Base Bonus" entry (and will edit that bit out soon); characters will use their reflex defense both to avoid explosions and to dodge the attacks of their enemies.
-Vitality and wounds. As in other d20 products, but cut vitality points in half and have them fully regenerate in between encounters. Plus Wounds are dependent on Brawn, which as a whole is the closest thing d20 Rethought has to Strength. And then there's Resolve and Trauma points, but while those are certainly a factor in combat they're a post unto themselves and would really confuse things here.
-Guard skill. Guard has two applications: Block and parry checks. Like attack types, these two checks function the same except that different equipment and feats interact with them in a different fashion. With a move action, characters can make a block, parry, or reflex check against a single opponent; until the beginning of the next round, the result can be used in place of their reflex defense against any attack that opponent makes.
-Armor as DR. Armor provides damage reduction, which protects against damage regardless of whether it'll reduce your vitality points or wound points. Armor can also be used to make block checks, with heavier types providing a large bonus on the check. On the other hand, one's reflex defense will likely be subject to a character's armor check penalty.
-Weapon Group skills. As mentioned in the "Combat Skills", proficiency in a weapon comes from having the relevant Weapon Group skill. So a fighter-type might find themselves weighing Heal against Weapon Group (Heavy Blades). In term of classification, d20 rethought's attack roll is a Weapon Group skill check.
-Multiple attack types. Just as there are multiple types of damage (piercing, slashing, etc), there are multiple types of attacks- swing (axe), thrust (rapier), bash (armor spikes), hurl (dart), and launch (bow). There are no special rules applying to any of these attack types, though a bash is normally a close-ranged improvised attack (such as with an elbow or sword hilt). Many weapons have more than one attack; as a hypothetical example, a longsword might say "Swing, 1d8, Slashing, 20" followed by "Thrust, 1d6, 19-20, Piercing". But small stat block differences aside, the real reason a character would want to, say, swing instead of thrust is because of situational rules- maybe your opponent is wielding a weapon meant for parrying and your Cleave feat only applies to Swing attacks.
-Two degrees of crit. Roll in the crit range of your weapon, and you have a choice. You can automatically maximize your damage dealt, or you can spend an action point and make a second attack check in an attempt to score a dramatic success. Against an opponent with Vitality Points remaining, this means you can deal damage straight to wounds. If you're dealing damage to wounds already, a dramatic success is a called shot; you accept a penalty on your confirmation roll and strike the body part of your choice if you succeed. Characters who can spend two or more action points in a single round (through class abilities, feats, or being at least 5th level) can try to score a double dramatic success if the first confirmation roll is also a crit (though maximum damage straight to wounds is often lethal enough).
-Single-roll full attacks. You score additional hits for every X by which you exceed the target's defense, up to a certain maximum. (It may help if you start by thinking of it as rolling once and using that result for all of your attacks.) X is 4 when using a light weapon, 5 with a one-handed weapon and 6 with a heavy one. Most Flurry of Blows-type abilities improve the maximum number of hits you can score, though a few (such as attacking with two weapons) can reduce X by one or (at higher levels) even two. None of these reduction stack with one another, though.
-Full incorporation of the swift action. Like in Saga edition, the swift action is an integral part of the system; many special attacks and other actions require the expenditure of one or more consecutive swift actions before they can be used. Said expenditure can happen partly at the end of one turn and partly at the beginning of the next; also keep in mind that you can trade a move action in for another swift action. The 5-foot step is a swift action, and characters will also have to expend a swift action to threaten the area around them for the purpose of making attacks of opportunity.
-Tricks and Stances.
Taking another page from spycraft and similar faire like the book of nine swords: Stances grant you passive combat bonuses and abilities. You can only benefit from one at a time, and can assume a new stance as a swift action. You can also only use one trick at a time, even though some adjust how a normal attack works and others are attacks unto themselves. Both come from feats, and possibly class features.