Campaign Setting Events! [EMPIRE!, but not specifically so]

[Rizban]

I went with unhappiness to keep the modifiers simple- higher number is higher unhappiness and becomes a higher number to beat on a Diplomacy roll.

If I tried to make it a happiness, then the lower it got the more unhappy people would be, but then how do I mecahnically turn that into a 2d6+Diplomacy roll for comparison.

0.is "neutral". Positive is "happy". Negative is "unhappy".

You could have a set TN for modifying Happiness.
Negative scores give a penalty to the roll.
Positive scores require something additional to improve beyond just an action (such as luxury resources).