This started off as a reply to Chandrasekhar's post here in the religious happycap thread (http://forums.civfanatics.com/showpost.php?p=4487706&postcount=25), but I thought it might derail the thread enough that I might as well split it off to a separate discussion.

You might say that Joe and the other shafted players will get the religions by spread, even if they don't found it. How, I ask you? The founders know that their +3 (or more likely +4 or 5 by now) happicap increase will win the game for them. They're going to close borders, keep their thanes/disciples/zealots to themselves, and pull ahead, leaving the seven other players in the dust.

Hmm, doesn't seem so simple. You can keep your borders closed together with everyone else and gain an advantage... or count on the fact that everybody else is keeping their borders closed and their religion contained to spread your own religion to all the neighbors, thus giving them a powerful bonus and you yourself lots of allies. Plus you get the shrine bonuses.

Keeping your religion to yourself pays off if everybody else does it, but you lose the moment anybody else spreads it. On the other hand, all the founders are worse off if everyone does go on to spread it. Prisoner's Dilemma, anyone?

(Of course, this assumes that there are AI players in game so that you get diplomatic bonuses for them converting to your faith - human players are more likely to just take your religion and then declare war and take the holy city to themselves.)

It makes me wonder if there should be mechanics for actually giving human players benefits for being peace at others of the same faith, like somebody suggested elsewhere before. It might also boost the AI a bit in single player - after all, the AIs tend to form power blocks based on religion, and such a mechanic would reward the AIs while penalizing the human players who hoard their religions or just go on a killing rampage crusade, wiping out their own allies in the process. It'd also fit the game's theme of ideological wars quite well.

Thus remains the question - how should it be advantageous to be at peace with civilizations sharing your religion? Here are some suggestions, I'm sure you folks have better ones as well.

* Drastically increase War Weariness and unhappiness bonuses when fighting civs who share your own religion. Reduce War Weariness when fighting wars with civs who have different religions.
* For foreign trade routes, add +1 commerce to each trade route if it's to a civilization that you share a state religion with. If we want to avoid overheating the FfH economy even more, then subtract 1 commerce from each foreign trade route to a civilization you *don't* share a state religion with.
* Allow the construction of a building/national wonder that acts like a mini-shrine, providing, say, +2 commerce for every civilization sharing your state religion.
* Give units penalties/bonuses when attacking civilizations of same/different religion, representing unwillingness to fight your brothers in the faith.
* Adjust some of the Divine spells to be more powerful the more civilizations follow your faith.

These were the ones I could quickly think from the top of my head. Any others?

I'd suggest that, as trade routes are a city-city thing, that they should be based off the religions present in the cities... no match -> trade penalty. This is slightly more complex then just state relgions... if my city A, with the Order as state religion, establishes a trade route with city B, with the Runes state religion, and nothing else initially... then we have a trade penalty. If the Order subsequently spreads to city B, I benefit more from the trade. If Runes spreads to my city A, they benefit more. If they both spread, then we both benefit... as we're each profiting from the religious dissidents present in each other's lands.

If possible, I'd suggest an additional trade benefit if you're trading with a city that not only has your state religion present in it, but also has a temple of your religion there.

poor Grigori