River comparison in Bts vs DoC It's a great coincidence that the issue of the prevalence of rivers in the game is brought up in combination with the advantages that rivers bring, in particular the availability of hydroelectric power. This is a problem both on the current and on the upcoming new map because on the latter the available space has often been used to include additional rivers. In consequence, in many fertile parts of the world every tile is often adjacent to a river. I don't think that is problematic per se, because a widespread river network is among the reasons why these regions were wealthy and populous historically. However, it contrasts with how comparatively rare and isolated rivers are in base BtS, and puts into question some of the advantages given by rivers. Just to recapitulate, if I am not forgetting something those advantages are: +1 commerce on tiles that do not have unimproved forest/jungle/rainforest fresh water (health) irrigation (i.e. access to farms) access to watermills access to trade networks without roads (after Sailing, i.e. most of the game) +1 production with Levees power with Hydro Plants some wonder interactions: +1 food with Dujiangyan, +2 commerce with the Grand Canal Unrelated to that, rivers somewhat impact unit interactions: +25% defense bonus for defending river crossings (unless attacker is Amphibious) breaks road connection bonus unless bridge building is enabled (i.e. with Engineering) That's a lot of benefits with few downsides. They were arguably balanced in vanilla BtS because rivers were more rare and therefore strongly encouraged. There is very little strategy involved when every tile is river adjacent, on the other hand. This has manifested itself in requests to make Levees available to all cities regardless of direct river access to reduce this privilege of rivers, or the problem in balancing cottages/workshops vs watermills when the vanilla balancing factor of taking up a river tile is not much of a concern anymore. Hydro Power But let's talk about Hydro Plants first. I think the idea here in the base game was similar to the limitations I listed above. No power source was meant to be "the best" (at least before Fusion) but rather each had its drawbacks: Coal was unhealthy, Nuclear was expensive and risky, Hydro required rivers. That was fine until rivers became a given for nearly every time. This is actually more problematic in DoC because here there are way more power consuming buildings and the power unhealth scales with the amount of power consumed. The tradeoff being that if you can find cleaner energy sources or otherwise counteract the unhealth, you get access to more yield/commerce modifiers. Being able to easily cut that penalty in half in basically every city before one of the "tough choice" options (nuclear) even enters the picture is not the intended situation. From a real world perspective, hydro power isn't actually that simple to model. It's a fairly obvious and easily accessible source of power under the right conditions (usually, sufficient elevation gradients). However, using it just on any river, regardless of size, usually requires the construction of very expensive dams that take a long time to build, displace a large amount of people, and affect the natural course of the river. All the examples of the latter type are usually considered megaprojects, like Aswan, Itaipu, Hoover, Three Gorges. Their cost and negative side effects are why hydro power is currently not fully exploited even though it theoretically has a large untapped potential of green energy. An easy quick fix would be to restrict Hydro Plants to cities next to a river AND near a peak. I think this is a good solution because it would restrict Hydro Plants overall and keep them limited to regions that actually use lots of hydro power or at least have the potential to. It would also provide some more value to peak tiles which isn't a bad thing either. However, the issue with that is that it generally doesn't cover the dam megaproject type of hydro power. You could argue that's what the Itaipu Dam wonder is for (representing that and similar dams), but I think that kind of project is a bit too common to limit it in that way. The other idea I have is to add a generic Great Dam national wonder (maybe even with a limited number of global instances) that would be very expensive, maybe even produce unhappiness, and either provide power to all cities that share the same river OR enable constructing hydro plants in all cities that share the same river. However, then you could still have issues such as a Great Dam in Amsterdam (well... it's in the name) and nothing preventing that except potentially the prohibitive production cost. A more complex power system I want to briefly touch on that because it has been mentioned in the other thread. Generally it's possible to change city power from powered/unpowered to having multiple "power units" used up by buildings that consume power. In fact, most of that is already implemented in terms of "power available" and "power consumed" counts, simply because that makes it easy to determine if a city with three sources of power still has power after one goes away for some reason, and the consume count obviously is already taken into account on the health side. So it would be possible to have a power plant produce different amounts of power, and base hydroelectric power on things like peak adjacent tiles or watermills in city radius, or let nuclear plants produce a disproportionately higher amount of power. I am only reluctant to do this because it opens up some further questions. What happens if the power consumed exceeds the power produced? Do all power consuming buildings stop working? If not, by which logic is the remaining power distributed between the buildings? Implementing this is one thing, but I feel it is tough to make this apparent. River limitations and possibilities in the engine It's important to note here that rivers themselves are wired pretty deeply into the engine. At this point, the only thing that is known related to rivers is whether a plot is next to any river, and whether the connection between two plots is a river crossing or not. The course and graphics for rivers are rendered based on this information by the engine and these properties cannot be changed really. As for moddability: There is currently no way to know if two cities on a river are on the same river, but that could be implemented. There are some complicating factors though, for example two cities could be on different rivers but both could still be on the same river as a third city because of how tributaries work. So determining "downstream" cities is easier than determining "upstream" cities. It is likely possible to implement river "types" with some amount of effort (see below for ideas). This would be on top of the simple "is river" tile property and essentially unrelated to how the game understands and places rivers. This could be used to affect which of the above advantages (or potential downsides) affect a given tile depending on what makes most sense for the geographical situation. It is probably impossible to represent different river types graphically in the game, as there is only one set of river textures used regardless of the tile. I don't think there is a way to interfere with that, although there may be a hack I am not aware of. River (section) types and distinctions I could think of several distinctions for rivers: Fertility: this is a river distinction that is already represented in the game, via the floodplains feature. Some rivers carry lots of fertile sediment to its shores that increases the agricultural output. Flow speed: would be implicit in the rule proposed above for hydro plants. This would make it more obvious: river sections would be declared fast flowing when near mountains or with sufficient elevation gradient and hydro plants would require fast flowing river sections. Navigability: rivers are usually only navigable up to a certain point. This is usually a hard limit for development, see for example the Nile cataracts being the effective borders of Egypt in different points in history. River shipping is very important for trade and it makes sense to tie the commerce bonus and trade connection properties to navigability. Width: I also think differences in river width aren't appropriately accounted for and they could matter a lot. There's a big difference between crossing the Danube in Bavaria and crossing it in Romania. Crossing a wide river could consume all remaining movement points, provide a +50% defense bonus, and require a later tech for bridge connections. Going even further, Estuary crossings could be fully impassable but instead provide extra commerce. I'm not proposing that a single tile could have yes/no properties across all of these different categories, because they are often interrelated. Floodplain river sections are usually also wide and slow moving, for example. So it should be possible to come up with types that combine the ideas behind those distinctions reasonably and have the corresponding benefits/effects. Further opportunities for river effects With this, there are other river-related rules that might be considered, especially based on different river types. A major historical concern that is currently not properly reflected is flooding. Often, the richest and most fertile rivers were the hardest to control and the ones that caused the most flooding. I don't know if there is an event for this, but even if there is I don't know if that is sufficient to represent the problems many civilisations had with flooding and the amount of labour it required to address. A good solution I could think of is a rather frequent event, most common along floodplain rivers, that places the "flooded" feature on adjacent tiles which can be cleaned up by workers similar to fallout. Its effects shouldn't be drastic but noticeable, e.g. -1F -1C and -0.5 health. This would require civs susceptible to this to keep workers around to keep this problem under control. The presence of a Levee would prevent such an event. Likewise, I think the idea of bridges in the game could be more developed. Historically, there weren't reliable bridges all along the river, and instead a bridge was the sign of a well developed city. Regular bridges along a river didn't become a thing until the Industrial Age and still aren't for many parts of the world. So I might consider only allowing penalty free crossings over rivers when it is through a city, and allowing them everywhere only with e.g. Railroad or even Infrastructure. Maybe a Bridge could even be Classical era building unlocked by Cement or Engineering providing this and maybe a trade related benefit. It's kind of weird that bridges are just given to you for free in the game when they required a large amount of labour and architectural skill to build in the ancient world. Conclusion I didn't want to let this post peter out like that but I think this captures all my thoughts around this topic. As usual, it is open for discussion.