During combat and other periods of beat-for-beat action, events are broken into rounds. Everyone gets one turn per round, and every round lasts about three seconds. In these moments, players may move as many spaces as their score in Dexterity (one spaces equals 15 feet). Players may half as many spaces as their Dexterity score while also performing a simple action. Examples of simple actions would be picking up an object, drawing a weapon, unlocking a door, using a basic weapon, or starting a car.
A player may also choose to remain stationary and perform a more advanced action, such as lifting a heavy object, reloading a weapon, climbing a ladder, or operating a complex machine. Once again, common sense is the defining factor, and the GM has final judgment on how simple or complex an action is.
Of course, players always have the option to do nothing during a turn.