These are the ways I've found to gain and lose Piety in Europa Universalis 4 so far:
- Random events: +/- 10 or 25
- Declare war: +/- X depending on the target's religion
Twice now in my game as the Ottomans I've been cooking along at +100 Piety when a conversion succeeds. I open the Religion tab only to find I've dropped considerably with no explanation: to +45 one time and +15 the other.
The second time happened very quickly. Within the space of two months starting at 100 Piety my leader died with an heir, I received a -10 Piety random event which should have dropped me to 90, and I converted a province. But the Religion tab showed me at +15 so something must have dropped me to +25.
Do you lose Piety when a leader dies, or does each leader come in with a random Piety?