With the issue of inbreeding raising its head last session, I think we need to establish some sort of rules about it. Here's my suggestion.
1. You can marry two people who share no grandparents without problem.
2. If you want to marry people who are related closer than that, from sharing any grandparents and up to being first cousins, you must ask the Pope for a dispensation. This is done by asking the current Papal controller (PC) for permission for such a marriage. The PC is free to demand any sort of favors, bribes, whatever.
3. If the PC is an AI ruler, you must send him a gift of some large sum of money, say 1000 gold. This must be witnessed and confirmed by at least two other players (i.e. they watch the PC and confirm that his gold increases by 1000).
4. Once a dispensation is received, it cannot be nullified, even by another PC in the future.
5. Dispensation cannot be granted retroactively, so you better watch who you marry. However, if a forbidden marriage is discovered, the husband (if a player) has the option of getting an annulment for it. This would be done by editing the game to remove the marriage and make all children resulting from it bastards.
6. Marrying anyone closer than first cousins (uncle and niece, half-siblings, grandfather and granddaughter) is forbidden and no dispensation can change that.
7. If someone knowingly arranges a forbidden marriage and refuses to annul it, the PC has the right to excommunicate the unlawful husband and wife and their children regardless of anything else. The ruler who arranged the marriage (usually the husband's liege) can also be excommunicated, but not anyone else.
For simplicity I also suggest that this applies only to players' countries. Let the AI inbreed all it wants.
