One limitation of the existing event system is that we cannot control when they appear. This isn't such a big limitation when they represent events that are beyond human control (earthquakes, birth of geniuses, etc.), but it does prevent us from being able to add "extra commands" to the game via events. Imagine an additional menu of options that are event triggers. These 'events' could represent legal decrees (i.e. Edict of Nantes), the construction of buildings, and any actions that can't be represented with the game engine. They could appear on the list of possible commands when certain conditions have been reached, and their effects would be normal event effects. This would give players a larger degree of control over "internal policy" - instead of having the ToT event pop up whether or not we wanted it to, the Portugeuse player might choose not to trigger it right away. The advantage of this would be that modders could add their own domestic action events...
You could even have certain "actions" that represented diplomatic actions - like buying foreign advisors, asking the Pope for permission, etc, which would trigger series of events...
You could even have certain "actions" that represented diplomatic actions - like buying foreign advisors, asking the Pope for permission, etc, which would trigger series of events...