A sort-of-generic Dark Lord (Gargravar) is getting ready to attack the Good Guys (everyone else), and the job is to mobilize the somewhat fractious Good Guy factions to fight on the same side. This was the year that Rope Trick became such a popular spell for clandestine travel that the next year's con was filled with Wands of Rope Trick Detection.
PrinceCon X was also a complete rewrite of the conbook into almost its current form, and introduced generic spells descriptions, metarules (bless-type spells don't sum), and expanded lists for various gods, with a common spell description section. This was the con that completely developed the overarching theme concept. GM's wrote two scenarios: an "external" one that was basically terrain surrounding Kalguz and hazards (such as orcs). These were to be distributed so any GM could run them. The "interior" scenarios were personal to each GM and contained the major thematic material and the objectives for commando-type raids.