Hey MonkeyBoy. I don't have the book in front of me at the moment but I believe you will find out more about it in the combat section. It's really well done, I just have to wonder if there is going to be too much rolling going on during combat.
1 roll 'to hit' (against passive defense)
1 roll for defender (active defense or shield defense). Note: this can be rolled at the same time as the 'to hit' roll by the attacker - this is just as easy to 'look-up' a defender's AC.
1 roll for damage
1 roll for armor (again, the defender rolls this at the same time as the attacker rolls his damage).
Overall - the attacker has the same amount of rolls. Only with OGL Ancients, the defender now gets to roll (at the same time). While this may take a bit more time - I think the defender (person getting hit) will feel he has a bit more 'control' over his own fate/defense!