I tried to cover the basics about this.
And about the speed/energy, I thought it would be relevant since you can run away from enemies (Like 2 steps = 1 tile away).

http://i.imgur.com/KfiX2gq.png

(I wasn't able to pick the right version at the options)

Minor edit: B idled, not C. And forgot to add: If all players end their turn before the timer ends, it also triggers the next turn.