**Updated for June 2019 IZ changes! See the updates tab for much more!! **
See below image for what I'm referring to in this text.
Many players enjoy getting the most out of their districts. It is a wonderfully fun addition to empire building in Civ6. Several unique districts have special adjacency mechanics. However, among all unique districts, the German Hansa (Vanilla) and the Malinese Suguba (Gathering Storm expansion) both possess the same special attribute: they have (1) a major adjacency bonus (2) for a specific district (3) that stacks.
For the Hansa, it pairs with the Commercial Hub.
For the Suguba, it pairs with the Holy Site. (Note that it loses the bonus with harbors, unlike a normal Commercial Hub.)
Many do not realize these specific bonuses stack. With that in mind, the natural question is "how do I make the most of it?" It's a puzzle with many options - and meticulously planning every city is a headache.
That's what this resource is here to help with! As long as you have open terrain, one can devise several standard templates to work with to ensure high adjacency in every Hansa (or Suguba.)
The Hansa has both a Commercial Hub adjacency bonus and a resource adjacency bonus. These templates most ignore the resource aspect - however, some variations are shown specifically to make it easier to move the template around and drop it where resources help you make the most. For the Suguba, it has only bonuses from Holy Sites and Rivers. Otherwise, in these templates, you can directly substitute Hansa for Suguba and Commercial Hub for Holy Site. While a Hansa template may be place to help align with resources, a Suguba template ideally looks to get them on a River or, if you have taken Desert Folklore pantheon, placed so the Holy Sites can really get a lot of boost from that.
Going through the templates:
These are the most basic shape. You only need two cities, and it's very compact. It's not as efficient a use of your limited number of Hansas - you get one per city- but its handy for situations like settling out on a peninsula or impassable terrain blocking things.
These are very simple and easy to fit shapes. Having the Hansas at the edges is usually easier to line up with resources. Having them in the center gives them extra adjacency since each Hansa is now touching 4 districts. Recall that all districts have +1 yield per 2 districts adjacent, regardless of what they are.
Sometimes, you end up in a situation where there's not a lot of free space or you have a luxury resource blocking things. Not to worry - the Ring is specifically there to help build around a central resource. This also relaxes how close cities need to be. A city can only build 3 tiles away form the center; in the ring, the central tile doesn't get built on and thus can be 4 tiles away from the cities if needed.
This is usually one of the best layouts for 3 cities you can do if you ignore resources. The central Hansa just needs one district dropped next to it to get yet another point for having 6 districts around it. (Not a bad spot for a government plaza.) You can invert the Hansas and Hubs, of course, if it helps fit around resources better. Sometimes you just get lucky with the map.
The biggest benefit to doing this is that it makes it very easy to get all your Commercial hubs along a river. One may also notice that the Snake is basically an inverted Crescent with an extra set of districts tacked on the end. When it this useful? Well, sometimes you have space to settle another city in the hinterlands later. Why not put it to use?
Here is where we start to come to a divergence between the Hansa and Suguba. Production is local, so sometimes we may want to favor a particular city (Say it has a governor, or Ruhr Valley, or something.) Gold and Faith and global, so we just want to get the most yield out of our Suguba.
I have included two reference layouts using the same shape for 4 city cluster designs. The goal is to maximize the output from some Hansas while leaving others weaker. You could put the fourth Hansa anywhere, really. Note that Emphasize 3 gives 25 total production while Emphasize 1 gives 26 total. (This matters for malinese players- it is a little better average than the 3 city designs which mostly give +6 average.)
When you have 4 cities, there are a ton of options, and often resources and wonders can get in the way. There's nothing wrong with taking a standard 3 city template and adding onto it, like how the snake was formed. This is also true if you can finagle 5 cities with overlapping district placement areas.
Upon realizing the bonus stacks, you may have wondered if it is possible to fully surround a Hansa with 6 commercial hubs. Yes, it is possible. The layout is more stringent in that you are fairly locked into where the city centers can be located. (Whereas with fewer cities, they can 3-7 tiles apart, here they must be 3.)
This will get you a central district with a monster +15 adjacency - for Mali, +17 if they can get on a river.
The OP of these threads shows an example implementation. It isn't too hard- you just need to not have mountains etc in the key spots.
The Hansa thread details step by step how to setup the layout (Any of the 6 cities can have the +15 district, only one permutation is shown in the image!) Note that any tiles in the outer ring of +5 Hansas have the special property of being within 6 tiles of all 6 cities. This makes them ideal spots to plop an entertainment complex or the colosseum.
While this guide has detailed how to get a lot out of these districts, there is also a strong motivator for why.
In both cases, putting a lot of cities close together is a very strong way to play civ6. You get more copies of districts in the same space. With the Production Queue and Multi Queue in Gathering Storm, management has also become easier than ever. A second upside is that you can get a lot of value from regional effects like the Colosseum or entertainment complexes.
In the Malinese case, it is simple: Mali is very gold and faith oriented; getting as much gold as early as possible is how you get the most out of the civ. I should also point out that the governor Reyna has a promotion to grant +100% adj to commercial hubs and harbors in her city; further the "Free Inquiry" Golden Age dedication in the Classical and Medieval Eras grants science to all Commercial Hubs and Harbors based on their adjacency, 1:1. This means that, if you built a Crescent in your first 3 cities, and place Reyna in the +8 city, you can get 26 science just from those 3 districts on a classical golden age. Not bad.
For Germany, production is a very very valuable yield. They can use these layouts to create high production cities in otherwise unproductive terrain. In Gathering Storm, as of release, the new Coal Power Plant grants bonus production equal to the adjacency of the Industrial Zone it is built in (just like the shipyard.) Normally, an Industrial zone in a great location could pull in +4, possibly up to +6. But as you can see, these Hansas can easily haul 5, 7, 10 production (if you get resources involved) or more. Like the Shipyard, the Coal Plant works with +100% adjacency cards; if you run Craftsmen or 5 Year Plan, this can make a single coal plant worth 10 or 20 production - or more! There is also a dark age card starting in the Modern Era, "Collectivism," which does a few things, one of which is grant a further +100% to Industrial Zones. This can push a Hansa all the way to 45 production just on the tile, with another 45+ from the coal plant. (It's possible to get lucky and reveal strategic resources later underneath districts. This resource still applies to Hansas, so you could pick up extra points, potentially surpassing +15 base. A nice trick to know for when you settle a city on a luxury or strategic resource as well.)
Germany also has an extra district slot for all cities, making getting these laid down very easy. A size 7 German city can fit a Hansa, Commercial Hub, Campus, and theater square - giving you every yield you need even for high difficulties. Mali is incentivized to rush these districts to get its faith and gold balls rolling. In both cases, it is good to get the trade route capacity anyways.
There are more ways to slice this problem that just the ways I've discussed, especially working with the confines of real terrain, but I hope it's been useful to help get your brain juices flowing. Once you get used to using them, it is fairly natural to spot where you can drop Triangles or Crescents. You won't need to cover the map in pins!
Hansa/Suguba Guide 2019-06-23
Maximizing Hansa & Suguba Adjacency - Updated for Aqueduct/Canal/Dam changes