Divided in many city states

>Divided in many city states
>Most city-states are organized around the river.

Would the Geography support city states or would it snowball into kingdoms/empires?

Will your players care about that?

Btw, most city states in history turn into or were absorbed by an empire.

>Will your players care about that?

My players are literally autists in this aspect

Control of the river forks could lead to trade tariffs and would give economic power to that city state.
And with money comes influence.

While true the access to commodities could be a driving factor in securing an alternative route via the sea.

Is that Finland?

Reminds me of mesopotamia, which had both.

Orcs rule the land, but are deathly afraid of water.

Only civilization exists in small city states alongside the rivers, ramshackle land-bound villages and massive house-ships. The big lake where the rivers start/converge holds the not-Venice, the most sophisticated and advanced city state in the setting stationary entirely on water, connected to land by easily demolished bridges.

the city state that is upriver sends its armies downriver in boats conquering the other cities in succession. forming an empire as a result. it happened in egypt and it would happen here.

The mountains in the northeast look like a nice place to have nomadic invaders swoop in and try to take over the flood plains.

Orcish gunpowder empires when?

Never, orcs are too dumb to figure out fire. Now if a traitor taught them how to tame fire... Civilization will burn.

I'd say it'd snowball. City states tend to require enough isolation to survive as lasting entities. For example, Ancient Greece was so utterly covered in them because the landscape meant cities were isolated enough from each other and there's no real proper rivers to easily use for transport in Greece, you either have to march through the hilly, rocky landscape or go by sea. With rivers like yours depending on what scale that map is, it would be easy enough for a powerful city to take the others and keep them linked in a state, since rivers are perfect transport arteries.

Depends on scale of your map; the reach of a city should be "one half days March," limited by geographical features.

Kingdoms would rely upon fealty and serfdom/aristocracy legitimized by the crown. City states would be strictly local, and likely rise from xenophobia

thinking of ye olde egypt i'd say.... kingdoms?

Rivers allow various benefits. The use of easy transportation along the banks. A good geographical landmark for tradesmen to follow. People familiar with the river know to either go up or down its flow to reach the location of the city. This isn't to mention the benefits of fishing and freshwater access, which would give the city two basic necessities for humans to survive. If the river banks have good silt deposits, you also can bake mud into bricks. If the river floods on a cycle, it can provide natural tilling(Note: Not like the Nile, the Nile is the Super-God river.).

Other cities along a river can provide easy access to one another. Alexandria can send shipments down to Cairo, Dusseldorf can send shipments down to Cologne. Paris is built around the Seine, as Warsaw is on the Vistula. Humanity organizes along coasts first, rivers second, and usually use rivers that connect to the coast. City-states normally exist with territory around them, not just the city itself. And usually have client states. The Roman Republic really was just Rome the city, plus extras. A factor that many people don't realize is the importance of client-states to early civilizations. Much of the "Persian" empire was just the Medes and the Persians receiving aid and benefits from client states after linking them together in the Post-Bronze Age era. Rivers are like roads that you can use for defense, use to give water and life to your people, and you can travel on without needing to walk. Also keep in mind, domestication of horses was a slow task so river-rafts were usually the fastest way to get around.

It 100% relies on scale. If this is the size of Greece or Egypt, then kingdoms, whereas if this is the size of Germany or India, then City-states. With the mountains seemingly serving as a natural border, I can see the situation turning into an Italian situation, with many city-states that over time, coalesce into empire, such as Rome's 400 or so year battle for all of Italy.

Scale would be France + Germany

You know that empires and city-states are not incompatible, right?

Depending on how lax is the imperial power, there can even be competition and warfare between the different cities ruled by the same monarch.

But Egypt is way bigger than Germany...

France and Germany combined? Then city-state all the way. Assuming general Fantasy level of technology, and also assuming this setting isn't using Wizard Kings and teleportation circles to extend effective reach, then it would be nearly impossible for an empire to be able to take hold of the entire area. Maybe if they took control of the entire river, and there was no useful land for farming outside of that directly next to the river, but it looks like there is usable land outside of the river area.

I'm a historian and I have no idea where your logic is coming from.

What the fuck, are you on drugs? Several empires controlled way bigger amounts of land and some didn't even have this sweet river highway to make control easy as fuck. It also seems to have appropiate natural borders, making it hard for external foes to balkanize it in bad times, An Empire could easily try and control it all, specially if they manage to get some kind of deal with the people living on those hills. Or maybe the conquerors ARE the hill people.

But this doesn't need to have happened yet. Or maybe it happened in the past but the empire was unable to get rid of the city state organization and it collapsed.

I think that outside of the Asian continent, it's been historically hard to have a large empire that lasts beyond the life of it's founder. See Alexander and Charlemagne, which are my two examples, with Rome being the exception. Specifically how Germany was a collection of a whole load of smaller countries.

It's all a matter of organization, really. China achieved the dream early and capitalized on it. Even after multiple collapses, a writing system allows for control. You can take down who's doing what, have ledgers, legal documents. It's how Russia, which is fucked in terms of territory and rivers, with swamps all over the place and vast grass seas was able to keep track of itself in medieval times and cities were able to organize into states. The only reason it kept so fractured, despite having many settlements linked, was largely no one Russian Princedom being able to beat the others. I'm fascinated by Russian history, as its a black hole in terms of historical documents until the Greeks and Scandinavians came onto the scene.

Bronze Age civilizations want a word with you.

Germany was an empire for quite a long time.

Do you think the persian empire (for example) wasn't decentralized?

50 years is not long