what would the best cleric domain be for a theocrat (archbishop or high priest)?

[petermcleod117]

what domain would be the most useful, and which one would make the most sense?

the theocrats would be competing for power with mundane nobles trained from birth for political backstabbing, so they would need some kind of divine edge to survive.

[Tzardok]

Tyranny domain (for forcing your will on others) or Oracle (for discerning plots against you).

[Kaleph]

Domination, tyranny, law and inquisition seem all plausible choises

[Bayar]

Depends on what god they are worshipping.

[noob]

War.
The war cleric of war that worships war is so good at waging war that they rise up through the ranks in the army then once they are at the top of the army they use their influence to make more wars and recruit more and more people for its religion in the army until most of the army is worshipping war at which point it takes the control of the country easily and wage more wars.
The divine edge for surviving the backstabbing nobles is killing them in daylight with a regular edge while having the backing of the army (And the adoration of the masses because it is a war hero that goes in the frontline to lead the army through giving the example by stabbing opponents).
Before the coup the nobles do not see the point in killing their best soldier and once the cleric is a general then the nobles can not really kill their strongest general because the cost of killing it is high and that general is too much useful for the army and once the wars are chaining the cleric is in a strong position because without the cleric the wars would tear apart the country.
The best chance for the nobles to get rid of the cleric is using divination to know who is going to eventually take over while the cleric is still just a soldier.

[Biggus]

Community seems appropriate for a good-aligned High Priest, but isn't much use for the kind of political infighting you're talking about.

Planning and Mind give you some handy divinations and defences against divination (including Mind Blank if your level is high enough), and Mind also gives a +2 unnamed bonus to Bluff, Diplomacy and Sense Motive.

[Maat Mons]

My favorite social-skill-boosting domain is Herald. It gives a +4 sacred bonus to Diplomacy and Intimidate. It also adds Intimidate as a Cleric class skill. If Intimidate isn't your thing, the Joy domain would be fine instead. It gives a +4 sacred bonus to Diplomacy, and nothing else.

My second-favorite social-skill-boosting domain is Truth. It gives an untyped bonus to Sense Motive equal to your Cleric level. For some reason Clerics don't have Sense motive as a class skill. But you can get it with the Pact domain, the Apprentice (philosopher) feat, or the Martial Study (setting sun) feat.

The Mind domain gives a +2 untyped bonus to Bluff, Diplomacy, and Sense Motive. If you want Bluff as a class skill, I think you'll mostly need either the Dragon, Envy, or Trickery domains. Well, unless Apprentice (criminal) makes sense for the character. Or you qualify for the Aereni Focus feat.

If most of the aristocracy you have to contend with are of one particular gender, I guess the Temptation domain might be kind of okay. It gives you a +2 competence bonus on opposed Charisma-based checks. So mostly just Bluff. But it only works against one gender, chosen when you gain the domain. Interestingly, your gender and your target's orientation are irrelevant. I guess you just know what boys (or girls) like (https://youtu.be/8FBoEWtxWxM)? No, wait. What am I thinking? That's terrible. A mere +2? To only one skill? Which applies probably half the time? And it's a bonus type that you can easily get elsewhere? Who wrote this domain?

[Thurbane]

Depending on alignment, outlook and deity:

Charm
Commerce (although the special power is more aimed at working class types)
Community
Destiny
Domination
Envy
Fate
Fury
Greed
Hatred
Herald (seems a bit off thematically, but the powers and spells look to be a good fit)
Inquisition
Liberation
Luck
Mind
Nobility
Pact
Pride
Retribution
Spite
Temptation
Trade
Treachery
Trickery
Truth
Tyranny
Wealth
Wrath