I've never read the specific details of the system, but I've heard it mentioned, described and critiqued by a range of people. I understand the system is found in the game 'Exalted' by White Wolf (or whatever it is they're calling themselves these days). There may be precedent for it before this point, but I'm not sure.
It basically works like this.
Instead of initiative with alternating actions, everyone is assigned a place on a circular track based on a combination of their reaction speed and a randomiser. Like a clock-face, there is a counting mechanism that moves around the track...when it comes to you, your character gets to act. If you perform a quick task you move a little bit around the circular track with your action and it doesn't take long for the counter to reach you again. If you perform a complex task you move around the circular track a larger distance and it takes longer until it reaches your turn again. The most complicated of tasks might have you stay in the one place, requiring a complete rotation of the circle before you get to act again.
I see this as working well for reflecting the style of combat you see in many video games, especially side scrollers like the 'Street Fighter' series, or one-on-one 3D combat games like Tekken. It doesn't fit the turn by turn combat style that you see in games like 'Final Fantasy' but I'm willing to veer away from that style of combat toward more anime-style power battles if it makes storytelling more cohesive within the game.
The basic idea for Voidstone chronicles would be a 12-step combat wheel. Characters are randomly allocated a value from 1 to 12 based on their Mental attribute and the elemental value of the stance they are taking for the conflict. Fire tends to act more rashly, water tends to act more thoughtfully, air tends to move more quickly, while earth remains stalwart but slow.
The basic combat attacks would be a quick strike (that pushes you back three spaces around the circle), a medium strike (that pushes you back five spaces), and a big power strike (that pushes you back seven). The basic defenses would be a block (which only takes you back a single space and halves incoming damage if successful) or a dodge (which pushes you two spaces but completely ignore damage if successful).
Different elemental stances would open up new conflict moves, so would different weapons, classes, cultures or training techniques. Each specific action would be written up on a simple reference card for easy access.
You play the card, roll the dice, determine the effect, move the combat tracker around the circle. Seems simple, I'm sure it will only get more complicated with exposure to the real world.