"If you're entire nation is Buddhist, but one city is Hindu, that city should be pretty unhappy" "I also feel there should be some small happiness penalty for towns with religions conflicting the state's" not sure where you missed the comparison... "In foreign diplomacy, if your Buddhist border cities are next to a Toaist nation, both nation's cities should suffer some unhappiness." or are you hung up on this... Actually I'm not real sure where the poster was going with this. It seems like an open-ended incomplete thought. Are we referencing the former sentence if, say, your state religion is christianity, and you've just conquered buddhist territory, now bordering a taoist rival? Yes, I think it should be near-impossible to maintain order, without heavy military influence or some policy (civic) to relegate tolerance, for some time. There may be a chance of those cities even seceding to the rival if he has one or more buddhist cities. If he just meant "my rival with whom I share a border has a different state religion", the statement is pointless because civ4 diplomacy mechanism already operates as such.