I wasn’t quite sure where to put this (we probably don’t need another old world thread), but in the process of figuring out some questions I wrote a guide of sorts. I figured this thread would be the best bet for someone finding it useful, and also people telling me if I my experiments and speculation got some stuff wrong. And yes, some of this is quite directly covered by the game’s tutorial, I just tried to make some of the explanation relatively self contained.
Old world: a quick start guide for players of civ
Part 1: How do cities work?
Cities can only be founded in pre-determined swaths of hexes, and those sites can be claimed by any sort of unit that stands in its key focal hex. Most of the map starts with those hexes pre claimed by either barbarians or tribes (minor nations you can conduct diplomacy with). As long as no one else is claiming the key hex, your settler can settle itself anywhere in the urban hex cluster. When you settle, your starting city borders are a minimum radius of two from your settled hex, and a minimum radius of one from all other connected urban hexes. On top of that, any bonus resources that lie at those radiouses +1 also get added to your territory*.
Once your city is founded, the exact set of hexes in its territory is not immediately relevant to the city’s output. In fact, if you never use a builder to construct hex improvements, it never will be relevant. So, what are the most immediate relevant values of your city’s output? They are growth, training, and civics, and together they loosely correspond to ‘production’ in civ. Growth determines how fast settlers and workers are trained (and is a completely separate concept from food which is a stockpilable resource). Training determines how fast most military units are produced. Civics is a sort of catch all of speed in ‘anything else you might order your city to do’. All of these three ‘production’ resources start with a base of 8 per turn in a new city, and ramping them up is usually a slow proceess.
When you order a city to produce something, the relevant one of the three resources starts filling up the bar, and the other two values are sent to their default locations. For civics and training, that means nationwide stockpiles that can be spent on various things (though normally not pumped back into city ‘production’). For growth, if it is not being spent on a unit, it fills up the city’s growth bar, eventually resulting in a new citizen. New citizens, it should however be noted, do not (unlike in civ) provide many benefits in of themselves, and in fact cost some gold and food upkeep.
So, what about the other resources? Science starts with a base yield of 1 in each city and is probably the hardest output to increase. Gold, food, iron, stone and wood output can all be increased by builder built improvements, and interestingly there is little direct link between a city’s population and how high these can go. Simply build the improvements in the best locations and watch the resources come in. However, if you want to start ramping your ‘production’ resources or science output, you will want to start improving those builder built improvements. That is a process where you select a hex where a builder has put an improvement, and use the city’s civics production to assign one of your city’s unassigned citizens there. Most hex improvements are valid places to assign someone, but for basic resource improvements you will get more out of them if it’s already a bonus resource.
One last resource that hexes/assigned citizens can put out is culture. Unlike in civ this has little to do with your city borders. Instead, each culture level is a victory point toward winning, and unlocks certain higher level options, like some wonders. On top of that, you get a small guaranteed nice event when your culture bar fills up.
So, if culture doesn’t expand your territory, what does? First of all, every ‘urban’ improvement your builders build claims all adjacent unclaimed hexes (shrines are probably the first such improvements you will notice). Normal (rural) improvements can also claim adjacent hexes, but only when they have a citizen assigned. In either case, the new claimed hexes also claim special resource hexes an additional hex away, just like with city founding.
Part 2: how do units work?
Units are limited to only 1 military and 1 non-military unit per hex, though they can freely pass over each other. How far they move is limited by two things, the actual movement statistic, and the fatigue limit. The movement stat itself is how far one order’s worth of movement gets you, the fatigue limit is how many move orders you are allowed before you have to force march which is far more expensive. Strictly, though, there is little limit on how far a single unit can (expensively) go in a single turn.
Units can spend orders in three ways. One is movement, as described above. The second are non-cooldown actions- these are rare (the only common ones I’m aware of are harvesting resources outside city radiouses, or chopping wood). Non-cooldown actions simply spend the order and don’t directly affect the unit. The third way to use orders on a unit is on cooldown actions, these will effectively end the units further movement or action this turn. This includes most common actions like builders building, military units attacking, or spending orders to heal or promote a unit. One easily overlooked detail is that these don’t interact with your fatigue limit- so, crucially, you can move your entire limit and then still build or attack.
So, how does attacking work? Each unit has a combat value, and whenever an attack happens the attacker and defender combat values are compared. Each unit has exactly 20 HP and my experience suggests an attack does about 5 HP of damage if the two numbers are equal. Barring extremely lopsided engagements you probably won’t see much higher than 10 HP lost per attack. Regardless, it is rarely simply the base combat values being compared, most promotions and terrain effects can add multipliers to either unit. Previous damage to either unit, however, is not usually relevant.
Healing damage works similarly for both civilian and military units (note, though, damaged civilian units can take longer to finish multi-turn actions). If a damaged unit is in friendly territory but is not engaged in a cooldown or multi-turn action, 1 HP is restored automatically. Any unit in friendly territory can also restore 5 HP as a cooldown action (some generals also allow this outside friendly territory). Lastly, a few hexes can boost the passive 1 HP turn healing effect higher.
Experience points and promotions are a feature of some military units- notably militia, mercenaries and civilians units are not eligible. If a unit is eligible for promotions they can always be simply bought with training directly from the global training stockpile. However, each XP collected reduces that training cost. XP can be collected by making attacks, sitting on training improvement hexes, and being commanded by some generals. Note, however, that being attacked does not yield XP. Promotions are limited to 5 per unit, and each new one becomes more expensive. Some generals can also provide promotions on top of the built in possible 5, but those will eventually go away when the general dies or moves on. Generals also accumulate XP in their own separate XP bar for making attacks, however their limited lifespans means they usually only level up once or twice.
Part 3: how do characters work?
Let’s break down the different characters you will be examining the features of, by relevance:
Tier 1: Your ruler
Every character has an archetype, which normally determines what kinds of roles they can be given and what their basic stats are. For your ruler though, each of those archetypes gives a special set of bonuses on a similar order of relevance as your civilization’s inherent bonuses. In addition, your ruler’s set of traits sets their baseline relationship with all other characters (so, for example, if your ruler is witty or brave, other witty or brave characters will have an improved impression of them). On top of all that, your ruler will have a direct stat based impact on your global income of science, gold, training and civics.
Tier 2: Your heirs
For all the same reasons your ruler is relevant, the traits and archetype of your upcoming ruler will be. In addition, even before taking the throne, the first 4 characters in line of succession affect your resources with their stats in the same way as your ruler, but to a smaller degree.
Tier 3: Your spouse(s), and courtiers
Like your leader and hiers, these all affect your resources with their stats. If you are wondering who is a courtier, they are usually special characters that come to your nation via an event, and have fewer role restrictions** (and if you go to the characters tab → court members filter, there is a subheading for them). Your relationship with your spouse is also relevant for the likelihood of new hiers. It’s also worth noting that your ruler’s relationship with any resource affecting character gives a bonus or penalty to that resource effect. The levels are:
-100 and lower, no positive effect,
-99 to -1, 50% positive effect,
0-99 baseline
100-199, 150% positive effect
200+, 200% positive effect
Tier 4: Heads of families, nations, tribes and religions.
Unlike with the above, you don’t really care about the stats of these at all, but your ruler’s relationship value is relevant. The exact benefits received vary with what they are head of, but the relevant ranges are the same as the table above. There is a little more granularity with heads of nations/tribes, however, because the specific number is used as a factor in various diplomatic decisions.
Tier 5: The non-head members of your aristocratic families and the extended royal family (that is, anyone part of or married to the royal family, but not a ruler, ruler-spouse or heir)
Now we are back to caring about the actual statistics and archetypes of the characters. While they can’t normally directly impact your resources with those stats, they can be assigned to roles like generals, governors or council positions (which ones are an option is archetype based) where the stats do have relevance. Since these people won’t really do anything until you assign them somewhere, they are mostly pretty invisible until you need them.
It’s also worth noting here an extra wrinkle for assigning characters is that cities and units won’t accept governors or generals of the wrong families- they have to either be from the same family, or the royal family.
Tier 6: Not in your nation, not head of anything
These are technically modeled by the game, but you will rarely have opportunity or reason to interact with them. The only edge case I have found is that if you select the ruler of another nation, it will show their family, and those can be selected for influence or assasination. So conceivably you might want to diplomatically prime or assassinate an upcoming hier.
Part 4: easily overlooked details
-Workers, settlers, ships and scouts can all use orders to collect lump sums of resources from bonus hexes outside of any city radius- however only workers are allowed to cut down forests for wood both inside and outside your city radiuses.
-Many urban improvements unlock new improvements that are similar, but better, and with a culture level requirement. This is especially noticeable in the case of the improved versions of the garrison improvement, which are always how you access your nation’s unique units.
-If a hex can provide a luxury, it needs both an improvement and an assigned citizen to actually create the luxury, then you need to click the tiny gem button in a city screen to actually send it there.
Footnotes
*One small edge case, stray urban hexes get added to territory in the same way as bonus resource hexes, except they also instantly chain and act as if they were part of the starting swath of urban hexes.
**To be fully precise here, normally each archetype allows exactly two roles, However, your ruler is always allowed to a general or governor regardless of archetype, and courtiers are always allowed to be general, governor or agent, regardless of archetype