In the middle and later game stages, players and AI factions could occasionally be given the option to construct "disruptive [planetary or system] improvements" that come with strong debuffs on neighboring systems, or greater chances of negative random events in neighboring systems, both incurring a diplomatic penalty if those systems are controlled by other factions.  Later-game disruptive improvements would have buffs/debuffs of greater strength than those available mid-game.  Different factions would have different disruptive improvements available to them, tailored to their faction narratives and priorities.


Examples include:

     
  • Aggressive military scanners that increase sight distance and allied ship movement speed but disrupt recreational and scientific communications locally and in surrounding systems, decreasing happiness and research production in those systems.  (Perhaps a Cravers option?)
  • Advanced interstellar manufacturing plant that disrupts the fabric of space (or spews "polluting" subatomic particles) and slows down travel in nearby star lanes and, as a result, decreases trade income from routes passing through those lanes.  (United Empire?)
  • Experimental biological research facilities that increase research points but at the cost of increasing the risk of negative random events (e.g. disease outbreaks) in nearby systems.  (Sophons?)
  • Virtual reality facilities with addictive properties, which increases local tourism and trade, but increase unhappiness in systems nearby and those connected with trade routes.  (Lumeris?)


Because of these debuffs and the potential for diplomatic penalties, factions would need to weigh their options and decide if it's worth building them, and to carefully choose which location would be best to put them.  If diplomatic relations are impacted severely enough, the improvements' effects could be enough to justify a declaration of war.


These disruptive improvements would come with the following additions to AI, diplomacy, and politics:

     
  • AI would be able to recognize that debuffs were coming from a certain improvement built by a particular faction, and diplomatic relations would drop accordingly.  (AI would also need to recognize when an improvement was removed and the debuffs ended.)
  • If an AI sees that another faction's disruptive improvements are providing debuffs to a faction they don't like, diplomatic relations would improve slightly.  ("The enemy of my enemy is my friend.")
  • AI would be able to weigh if a disruptive improvement was worth constructing or not, given the mix of benefits and consequences.
  • Diplomatic options would include demanding that a disruptive improvement be dismantled, or requesting that a disruptive improvement be constructed in a particular system to provide debuffs to an enemy.  Factions could also request that another faction assist in destroying a particular improvement that's negatively affecting them, or to assist in convincing the owning faction to dismantle it.  (These could also take the form of quests.)
  • Political parties would have different opinions about certain disruptive improvements and your empire's political landscape would determine some of the effect of the improvement on your empire's happiness.  (e.g. Disruptive improvements that cause pollution would upset ecologically-minded political parties, and the significant extent of the pollution could increase membership in ecological parties.)  Neighboring factions' politics could also affect the extent to which the debuffs upset them and impact your diplomatic relations, making disruptive improvements dynamic and different in every playthrough.  Political parties could also serve as a prerequisite for some disruptive improvements (e.g. needing to have enough militarists to allow the construction of the aggressive military scanners mentioned above).


If the debuffs are significant enough, some disruptive improvements could also have graphical effects that appear in system or galaxy views to indicate the extent of their effect areas, such as a haze in cases where the improvement causes 'pollution', or ripples where star lanes and the fabric of space are disrupted.  (These would make sense for later game disruptive improvements where the negative effects of the irresponsible use of very advanced tech can be far-reaching.)


Overall, this addition would provide the following gameplay benefits:

  • More diplomatic options and more ways for players and neighboring factions to influence and be influenced by each other beyond traditional trade and declarations of war.
  • More ways to negatively affect opponents without declaring war (though they might make war more likely).
  • Additional strategic and diplomatic considerations emerging in mid-game to keep gameplay from getting stale.
  • More immersive demonstrations of the powerful effects of advanced tech.
  • More graphical eye candy in galaxy view.