From the introduction:
Elegant turn order design explores different mechanisms that model role-playing game character action sequencing.
Most commonly actions are taken in turns. Turns are born of necessity as real-time or simultaneous activity modelling would be impractical for table top game play.
Turns are not however the most elegant way to model the dynamic nature of play. Within the solid frame of turns can be found subtle nuances that don’t break the foundation but increase the flexibility and adaptability of the system.
A key consideration is how the focus moves between characters and their actions. You can think of it like a camera pointing to a selected character at a time. For example, in a classic initiative order the focus moves semi-randomly between characters based on their initiative.