Trajectory is one of the 12 Core XSE Dynamic Mechanics within the Derived Dynamic of XSE Dynamic Mechanics. It describes the developing course of the System of Interest (SOI) through time as its Current State and ongoing operation interact with relevant Forces, Energy, Inertia, Momentum, System Work, Gateway conditions, Sources, Resources, feedback, constraints, choices, and surrounding-system influences.
Trajectory answers the fundamental question:
Given Current Reality and the Dynamic Mechanics presently operating, where does this course appear to be taking the SOI?
Trajectory is distinct from Position and Desired Results: Position concerns where the SOI is; Desired Results identify where it intends to go; Trajectory describes where its actual developing course is taking it. Trajectory is not destiny or a prediction of inevitable outcomes—it is an influenceable course that may change as the SOI and the conditions acting upon it change.
In concise form:
Trajectory is the Core XSE Dynamic Mechanic describing the developing course of the System of Interest through time, indicating where its actual operation and changing conditions appear to be taking it.