Okay, so my second playthrough (Indonesia, Emperor, random map type and size which turned out to be Huge Continents) is nearly complete, and I can add a more detailed opinion on BNWs changes while I wait for Darius to finish his spaceship.
Trade Routes
Overall, this is the most coherent and best-handled of the new systems. It plays into many areas of gameplay, can drive your economy in much of the game without being essential for most of it (and so allowing non-trade focused strategies to work, although much less effectively), seems to be generally well-handled by the AI, and puts a high premium on city placement.
There are however (as with many features of BNW) apparent balance problems. It still beggars belief (and I raised it when it was first revealed) that no one seems to have thought being able to get 11 food trade routes early in the game would break the system, and even 4 food from caravans is valuable. Conversely, no one seems to have considered that food is worth a lot more than production, making production trade routes all but useless. In practice I actually have found gold trade valuable enough that food trade isnt all-dominating as Id feared, but it still needs to be looked at.
- Some disappointments are:
- that domestic trade is not at all reliant on city placement, as you dont gain the 25% bonus from rivers and resources arent counted. I think a good fix would be to give food trade a lower base, with a boost for each non-shared food resource (food resources, in previews, affected international trade bonuses, but dont in the final game for some reason). Production would get a bonus for each strategic resource in the same way (gold, as now, would get bonuses for every resource of any type).
- Poor scaling through the game makes trade routes less and less important, and resources less important relative to being on rivers (arguably the reverse of reality), since its a fixed 0.5 bonus however much income the trade route generates (and the reasons for the substantial differences in trade income between destinations are poorly-documented). Caravans also become irrelevant for anything that can be traded coastally as time goes on, and its rare for inland sites to be desirable enough to trade with them preferentially.
You also have no control over trade coming from other civs, such that your turn-by-turn income can fluctuate in a way its hard to plan for. While the current way of setting trade routes (i.e. without any need for explicit diplomatic agreements) works, it would be nice to also have the option to offer/request trade routes as trade goods (e.g. I give you X, you set up a trade route to Jakarta for 30 turns). This also makes East India Company less of a hit-or-miss investment.
Much has been made of the need to protect trade routes, however with changes to the AI that promote early-game passivity, I havent been under very much pressure to do this. It did mean that when I finally did go to war, with the Netherlands, I lost every one of my trade routes in short order, however, and I still got bankrolled by Arabias trade into my cities. More emphasis on the importance of this would also help caravans (which are more easily protected, and almost completely safe away from the frontlines in the late game barring rebel uprisings, as barbarian camps are gone) remain relevant into the late game you trade off lower income over greater defensibility of your trade routes.
Culture and tourism
While I still havent made a lot of use of this system (and to some extent am feeling the effects of neglecting tourism, although the effects of sharing ideologies with tourism-heavier civs make it easy enough to get away with this), my opinion that this is a system with great potential but heavily flawed implementation still stands.
I really like the Great Writer/Artist/Musician system in principle, although I feel the Musician is a little weak (the tourism effect, used aggressively, can be valuable, but only in quantity and requires open borders to use, when the opposing-ideology civs youll most want to affect are likely to be unfriendly. In contrast the Great Writers culture boost, as well as being valuable defensively, gives you a huge boost towards a direct product social policies). Probably the Artist too will prove to be somewhat weaker than the Writer in the long run, due to the great advantage of the culture boost effect and the reliance of Great Artworks on Wonders.
I dislike the generation system, however. With all other Great People, you have much more direct control over GP production rates buildings, number of cities spawning them, rates of faith production for Prophets, and of warfare for Generals and Admirals. Building a single National Wonder with up to two specialists gives you very little control and makes the system very passive, not something that will vary much with your strategy. Since each of the three GP types has its own GP counter (Writers dont share the Artist counter, for instance), there are no trade-offs beyond the need for specialists as there are with other GPs, so theres no strategic variety you will never have games where its worthwhile to neglect Musicians to boost Writer production, say. You go for all three buildings as soon as you have the food to support them, and get spamming. This makes for a very boring experience.
The Great Work swapping has attracted, I think, well-deserved criticism. I dont think it would be too crippling to, say, France to make swapping a diplomatic trade (and you wouldnt design a system around a single civs UA anyway if necessary, just change the UA). You can trade with anyone, even if youre at war, and it seems you cant lose Great Works or indeed loot them. I lost Makassar temporarily, however my tourism output was unchanged (although, as my GW and GM system, Makassar certainly had Great Works in it apparently they were reassigned to empty buildings in other cities). Its a bizarre and rather clumsy system, and anything that can be added as a diplomatic option in the somewhat limited diplomatic trade system typical of Civ games should be a tradeable option. It also removes any incentive for looting other civs artifacts (and the attendant diplomatic penalties) as long as you have access to antiquity sites of your own, since you can just dig in your own sites and swap for what you need.
This leads to archaeology, which is nice in concept but rather limited. Landmarks rely on having antiquity sites near your cities, and Ive rarely if ever seen more than one per city, so mostly youll be hunting for artifacts which have rather limited game uses and, as with artworks, few non-Wonder slots to house them. Also, with the peaceful early games that comments here and my experience suggest are now typical, there just tends not to be very much variety in or access to dig sites in or around ones own territory.
Culture victory now seems to rely more than ever on Wonder-spamming, since the big culture generator is the hotel, and only France and Polynesia get to choose cultural improvements (the tooltip suggests that only these and Landmarks give a tourism bonus to the Hotel, so GP improvements and Brazilwood camps are out, and landmarks cant be planned for in advance. Culture-producing Natural Wonders are also in short supply). Religion will also be very important the tourism for faith buildings Reformation belief will likely be fundamental, and Religious Art as well.
World Congress
I like the World Congress both in concept and implementation
however it is more badly let-down than any other game system (and yes, I include 1UPT warfare) by AI limitations. The AI could handle the old diplo victory conditions fairly well, aside from being lethargic about actually building the UN, but seems at rather a loss with the new one, beyond its old trick of grabbing city-states. It appears to use diplomats more than spies, but Ive never been approached for vote-trading and based on AI votes reported it seems unlikely that they trade votes with each other. This approach means it may not actually be possible for an AI to win a diplomatic victory (without several favourable delegate-generating resolutions), since under the new system a civ can have every CS as an ally and not have enough delegates to win.
As for non-victory resolutions, AI proposals seem somewhat stereotyped (World Fair early, usually an early attempt at a trade embargo). I havent been in a position to propose resolutions in this game, so cant comment on how this influences AI responses. I have seen some pleasing signs that the AI will vote in its interests. Ffor instance, I tried to block a proposal to ban cloves sadly unsuccessfully since I approached the wrong civs, Persia not being the power it once was diplomatically. I bribed Arabia, but tried to get Darius onside simply by trading cloves with him, so that hed be hit by an embargo. He obligingly voted Nay to the ban.
Mostly however the AI seems unable to relate Congress decisions to gameplay. For example, Babylon (host and city-state hoarder) tried to push through Autocracy (uniquely of the civs in this game, Nebby is an autocrat), but when it failed he didnt do anything to change his position although he would probably have benefitted from switching to Freedom once that became the World Ideology. Theres no World Religion, however if there were I suspect AIs would still object to you spreading it to them!
The new Diplomat option for spies is indispensible, so much so that I find it increasingly hard to justify using a spy in a CS, which will never have more than one delegate each. I suspect this may be a new balance issue. In any event, this change has been made without changes to the numbers of spies or opportunities for leveling them up (tech stealing is still the only way), and its important to have a high-level spy as a diplomat as it appears to affect the number of delegates theyre forced to commit if you obtain their vote. Another great addition that might require a little more thought.
The 30-turn gap between resolutions in the Congress also seems rather extreme. I see the need for a delay (you have to think hard about pushing for Scholars in Residence when you wont be able to reverse it for a while after you become tech leader), but 30 turns is excessive, and possibly done to avoid running out of resolutions.
Ideology
I havent played with many of the new options, or looked at the spoilers to learn what they are, plus so far Ive gone Freedom in both games. Mainly Ive seen the effect of ideology through its diplomatic impact, which is enormous. In short order after adopting Freedom (although possibly hastened by general distrust after a defensive pact forced me to declare war on a friend, and in Babylons case by my breaking an agreement to go to war), every non-Freedom civ was against me, former friends Babylon and Assyria among them.
This can have very pleasing effects theres now a large Freedom alliance, and following a revolution that overthrew his ordered government, Shaka has gradually been adopted back into the international community despite formerly being soundly hated by everyone except the Order-loving Egyptians and Assyrians.
It is, however, too extreme I anticipate that it will result in rather predictable match-ups and diplomatic endgames, and it seems that very little can be done to mitigate this diplomatically, however many accumulated positives you happen to have with a civ that adopts a different ideology. You basically out-tourism them into having a revolution, or thats it. Taking player actions out of diplomatic results so drastically will, I suspect, lead to an increasingly frustrating play experience it feels a lot like the last Total War games artificial Realm Divide mechanic. There isnt even an Adopt my ideology trade request option (yes, I keep on about that, but I think a lot of these should be included in the diplomacy screen).
Gameplay
In summary of the above, BNW as a set of new game mechanics is great in concept but somewhat mediocre and at times frustrating in execution. If this was all the game changed, I wouldnt have been playing it at every opportunity for the past two days.
The changes made by BNW are enormous far more wide-ranging in their gameplay effects than those in G&K, which was itself widely felt to be a whole different game from vanilla. Its possible this is the source of some of the numerous apparent balance issues: this expansion was released to much the same schedule as the previous one, when it may have needed longer to investigate how it all worked (although, as with food trade routes, Convert the Heathen is visibly overpowered even on a cursory examination).
Early game
Despite the expansions billing, this is likely to be where youll feel the effects the most. Changes to the tech tree, additions of several units, and both explicit rebalancing (lighthouse) and new mechanics that favour certain buildings at an earlier stage (such as amphitheaters and workshops) mean there are very few poor options to choose between, and much will be strategy-dependent. A library may now be quite a late grab, and I find myself prioritizing settlers much earlier. City location is more critical rivers and coasts are good, but in the early game a city with varied resources nearby may bring in more cash (you can always change your favoured trade city or cities later), so even thats not a binary decision.
Critical techs are now pleasingly spread around the tech tree, but the addition of quite a lot of new effects but no significant new techs means that some techs are more overburdened than others I think a few more techs to spread out some of these upgrades would have been a good move.
Obvious changes to barbarian frequency, behaviour and unit types add some nice pressure at this game stage as well, and this is the time when youll need to invest in defending trade routes. AI civs persecute barbs more aggressively, so no more leaving destroy the camp CS quests for most of the game now someone else would get there first. One disappointment on the subject of CS quests: why is there still a build a road quest? Roads still havent been adjusted to do anything useful when connected to other civs or to city states.
Of the existing game systems, the truly major beneficiary from BNW is religion. I cant say the Piety tree is overpowered now (except, of course, for Convert the Heathen), since I havent tried the others, but I certainly havent felt the lack for not going Tradition or Liberty (except in happiness, which admittedly is important). And certainly no other policy tree has a single policy that can affect your game as much as Reformation. I dont think they needed to remove the Rationalism restriction to make this attractive. Religion, with the right beliefs, can be a substantial source of tourism and possibly essential for playing a cultural victory; more generally it can overcome reductions in gold and happiness characteristic of BNW (and even mild unhappiness is now important, so those happiness beliefs take on a new significance), and if spread widely enough later in the game can have important effects on diplomacy.
Exploration is stronger than I realized, not least because the Lighthouse and Harbor are now fundamentally important buildings, and you may well want more coastal cities than in the past, while Aesthetics has so far had an apparently only moderate effect on my tourism, but there are still issues that need attention (the Great Admiral policy in Exploration, and indeed Great Admirals in general).
Past the early game, only AI changes (and the more aggressive barbarians) really make a difference to the way the game plays unless you suffer the effects of unhappiness which now produces production and gold deficits, and reduced military performance, for every point of unhappiness. This is a very good change previously unhappiness could be ignored if it was above -10, since its only meaningful effect was to depress growth and if you werent keeping your happiness up, you didnt want extra population growth anyway.
The science penalty for expansion appears not to be substantial, and certainly doesnt stop the AI from city-spamming more aggressively than ever; wide empires seem to be favoured by the increased importance of culture relative to science, both because of the loss of the cultural penalty for expansion and the way the tourism system favours playing wide outside the Wonderspamming production city (Great Work slots being tied to the number of buildings, more access to landmarks in a wider empire).
Late game of course the effects of ideology kick in, and the World Congress (something of a minor curiosity with the few resolutions available in the Renaissance) becomes relevant, which again will change the way you play, although less substantially than the early game. Indeed, if you pick an already-influential ideology you probably dont need to worry much about influence unless you actively want to steal nearby cities.