Quicknote: In combat terms, the round is the most important unit of time for players to remember.
Once reactions have been determined, and have led to a physical confrontation, combat begins. Combat is divided into units of time, as follows:
Round (3 seconds): Equal to 3 seconds of time. During the round, most mortals will be able to take a single, simple action. Many immortals can act multiple times within a clash. Some actions will require immortals to concentrate for an entire clash and be unable to do nothing else.
Action (one simple action): Within the round are actions. Most humans have a single action they can perform within 3 seconds, but the supernatural reflexes of immortals allows them to perform multiple actions within this short span. Immortals with a high soul rating move so quickly in combat as to be blurs, or unseen altogether.
Turn (10 clashes/30 seconds): Protracted actions, those that take longer to complete, are often measured in turns, minutes or hours. The first round is the beginning of a turn. The 10th round is its end. Because of their ferocity and speed, immortal combats rarely last longer than a turn. The most significant feature of a turn is that immortals can only allocate their soul energy at its beginning.
The narrator is the final judge on the time required for an action, depending on the circumstances and environmental conditions set within his story.
Scene -- An indefinite number of turns (decide upon by the narrator) makes up a scene. A scene lasts as long as a certain situation. Once there is a change of setting or combat is over, the scene is over and a new scene begins. Some supernatural effects caused by serenades persist until the end of the scene, making this measure of time important. A scene may last for a few minutes or a few hours. A narrator will usually let his players know when a new scene begins with a statement such as "Night falls," or "You finally arrive at the ancient manor."
Episode -- One evenings gaming, or a number of days for the characters.
Series -- An indefinite number of episodes make up a series. Think of the series as a book or movie trilogy. It is a single story which winds itself through many episodes and finally concludes in a master climax. Once a series concludes, players may wish to start a new game with new characters, or continue the first one to a second series climax. The more series a player experiences, the more history and power his character accumulates.
Indefinite -- Some serenades or effects have an "indefinite" duration. They may never expire, or may end at the narrators discretion.