Ac

[Gargoyle]

Big advantage of this system is that the previous one penalized high dex characters who were 'flat-footed' more than low dex ones, which always seemed kinda wonky to me (especially b/c dex penalties were still retained). Now your dex *always* figures into your AC (unless paralyzed) and a creature who has the 'combat advantage' *always* gets a benefit to their attack role. Simple, elegant, and (IMO) more realistic.

I like the idea of the attacker getting a bonus rather than the defender losing their Dex bonus, but I think a simple bonus to the attack roll is probably going to favor high Dex characters a bit too much. After all, a high level character or a creature with naturally high Dexterity might be able to offset a +4 bonus pretty easily, while a low Dex character would likely be hit. That might be ok. But it might not scale well if Dex scores keep climbing as you level. There are oo many unknowns, as we don't know how ability scores scale yet, of course.

A better way to scale it might be to allow a reroll if the first roll misses. That doubles your chance to hit, no matter what the opponent's AC or Dex is, and it seems like a fun option, but it also might be too big of a bonus. Another way would be to let the attacker crit on a natural 19 or 20...but I don't think there will be a return of crit threat ranges.

It's fun to speculate and will be interesting to see what they do with the math.

 

[Mustrum_Ridcully]

I like the idea of the attacker getting a bonus rather than the defender losing their Dex bonus, but I think a simple bonus to the attack roll is probably going to favor high Dex characters a bit too much. After all, a high level character or a creature with naturally high Dexterity might be able to offset a +4 bonus pretty easily, while a low Dex character would likely be hit.

I am not sure if I get you right, because it seems to me as if you are mixing Reflex Defense as Touch Armor Class and being Flat-Footed.

If both have the same AC, it doesn't matter wether it comes from Dexterity or Armor. The +4 is an equal "penalty" for both. The character with the higher Dex has a higher chance to avoid it the penalty in the first place, though, since he has a better chance for a higher Initiative.
Their Reflex Defense only matter in this situation if the attacker is also making an armor-ignoring attack (touch, incorporeal?).