As previously mentioned, a story's setting is one of the key elements. A setting can be defined as "the time and place of the action of a literary, dramatic, or cinematic work"; basically that means when and where a story takes place. Since they are also stories, this definition applies to adventures.
In WCRPG, most adventures will likely take place in the years following first contact between Terrans and the Kilrathi (the year 2629 according to the timeline in Chapter 12.1) though an adventure could just as easily take place earlier than that. Even from 2629 onward, there are a lot of ramifications of the year in which an adventure takes place. Adventures set in 2654 and 2655 will have to coincide with the events of WC1, Special Operations 1 and Special Operations 2. The period between WC1 and WC2 (2656-2664) will see a bloody stalemate in the Terran-Kilrathi War, with Christopher Blair banished to the Gwynedd system with his career in tatters (and the field wide open for any number of tales). 2665-2667 coincides with the events of WC2, with 2667-2668 coinciding with the events of the novels End Run and Fleet Action. Wing Commander III and the end of the Terran-Kilrathi War occur in 2669; an interregnum then begins which lasts until the Border Worlds Conflict of 2673. Peace reigns until first contact with the Nephilim in 2681, leading to the Nephilim War which lasts through the end of the 27th century. The next time anything "official" happens in the timeline is the year 2790, where events focus on the Tri-System. The Wing Commander Universe's broad timeline is only one example of how important the "when" aspect of an adventure's setting is. Smaller time scales can be just as crucial; a few minutes' difference determined the difference between Earth just getting nuked and being rendered uninhabitable by Strontium-90 warheads in Fleet Action.
As important as the "when" aspect of a story’s setting is the question of "where". Adventures in the Wing Commander Universe can happen in a plethora of different places; they can take place in such diverse places as the Commerce Exchange on Olympus, the fire caves of Firekka or in orbit around some unnamed world deep in the former Hari Empire. Moreover, given the use of all manner of vehicles, the location can (and often does) change rapidly even within a single adventure.
The following subsections of this sub-Chapter talk about the elements of location settings. Essentially, all adventures can be broken down into one of four types based on the locations involved: site adventures (adventures at a single location), planet-side adventures (adventures on a planet or moon outside of urbanized areas), urban adventures (adventures in a city or space station), and space adventures (stories that take place in space and usually involving some kind of spacecraft). The guidelines presented can be useful in building an adventure, including those that use more than one type of setting.