[Pocus]

Sunray made some intensive tests on scales, and the conclusion were that you would gain between 1/10 events (order +3) to 2 events (order -3) on average.
The repartition was in accordance with what the devs said, which was 50% chance of having a good event, +-10% for each luck scale.

Aside that, there is a bug with scales resetting on first turn (I just got it with a Mictlan test bed).

Also strangely, you can loose an heat scale even in summer, and without any event or exterior interference.