Pretty simple. 

Add some randomization to things like the curiosity quest and the academy quests.

Essentially, any event that triggers because of the game hitting a certain turn.

So instead of something happening on turn 15 it has a small chance to even happen at turn 10 or 20. Say turn 15 is the highest chance for the event to occur and then the % slowly drops off at turns 14 and 16, even more on turns 13 and 17 etc...