As usual, all of this is subject to further change, but probably less so than other sections.
Firstly.. the one-second rule will apply. PD have used this is Maelstrom and Odyssey. A number of smaller systems have picked up on this and it has proved workable and popular.
Combat will remain a global hits system. How many hits a player can take is not yet known.
Zero hits is unconcious, but not dead. Dying still involves a death-count.. but significantly smaller time period than currently in Maelstrom. Maybe only 150 seconds instead of 300!
Damage calls will be largely absent. Only special effects will be called. This makes the damage calls more audible when used, and hopefully makes magic in larger battles finally a workable solution.
Special calls will only be available to combat players a limited number of times per battle. Make them count!
So far, special calls are the predicable types. Stun, Strikedown, Crush, Shatter, Disarm.
One additional special that is implicit rather than called. Impale. Archers in Empire are big and clever. Impale will take you to instant zero hits.
Plate Armour is immune to Impale. Armour is big and clever. Unfortunately.. it's also OC expensive. but there are BIG BIG advantages in Empire to being able to wear heavy armour. There are about 6 different levels of benefit from wearing more and more expensive/heavy armours.
The counter for us of course is the light armoured mage with strikedown (even in plate mail.. asses must hit the floor. Let's see them get up again before the mage mashes them to pulp with a staff after that....)
Shields are useful... shield walls are even more useful... Shields can shrug off some of the nasty calls (Impale, Strikedown, Stun). Put mages with Shatter in second rank...