Sequence

Each character actively involved in the
combat gets one opportunity to act per
second, referred to as his “turn.” After
everyone has taken his turn, one second
has passed.
the one-second time scale. This is just a
way of breaking a battle into manageable
chunks! He should feel free to drop out of
combat time whenever dramatically
appropriate, and to resume combat time
when noncombat action gives way to more fighting. Consider a running
gunfight in which the combatants leap across rooftops and chase each
other up and down rickety fire escapes: the GM could resolve this
through roleplaying and DX or skill rolls (against Jumping, etc.),
interspersed with a few seconds of combat whenever he feels the
opponents have a clear shot at each other.