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Good news everyone!

Today we are going to share some details with you on how the galaxy is generated in Stellaris. When discussing this we will also touch on some of the different features of the galaxy and how we try to anticipate what modders will want to do with the galaxy generation in this game and making sure that they will be able to.

When you start a new game you can specify the size and shape of the galaxy as well as the number of (normal) AI empires. Sizes currently range from 200 - 1000 stars. The amount of AI empires only affects how many AI controlled empires that are generated from the start, a lot more will spring into existence during your game. Currently we have three different types of shapes for the galaxy; spiral, elliptical and ring. Spiral galaxies have the stars placed in arms that extend out in a spiral pattern (see “Pinwheel Galaxy”). A spiral galaxy provides an interesting geography, with voids between the arms that might be difficult to pass in a straight line. Elliptical galaxies have the stars placed in a ellipsoidal pattern (see Wikipedia), resulting in a more evenly distributed geography. Ring galaxies have the stars placed in a ring shape around the galaxy core (see “Hoag's Object”). If you play with a ring galaxy you know that other empires have to approach you either clockwise or counterclockwise within the ring, making it easier to cut other empires off from the rest of the galaxy than it is with any other shape. All of these options are of course moddable, both in regards to looks and available options.

Once you are satisfied with your options and decide to start the game, we begin the process of generating the galaxy. When we generate the stars we also decide what class each star should be. Most stars will be star classes with the different spectral types B,A,F,G,K,M. Some star systems can however be more special, like a black hole, pulsar or a neutron star. Every system with a certain star class has a given set of rules that controls how the star system is generated; you will, for example, have a hard time finding habitable planets close to a black hole. All of this is very moddable, you can add your own star classes and remove the existing ones if you want to.

stellaris_dev_diary_03_02_20121005_pulsar.jpg


We also generate some galactic features other than stars. One of these are nebulas. Nebulas are visible on the galaxy map and often contain a bunch of interesting star systems with special rare resources. In a nebula you can expect to encounter some special events and experience certain penalties and bonuses that may impact your decisions when it comes to colonization and fleet movement.

When we generate the contents of each star system we use different system initializers depending on what the system is being used for. If you, for example, were to start as a pre-scripted human you will be placed in our solar system, on Earth. Yes, all of this is moddable also. These initializers allow us to make sure that you, as a player, will always have something interesting to do within a system. They also provide us with ways to create a more balanced start, by being able to affect the content of your star system and systems that are neighboring to yours. It is worth knowing that these initializers have a certain random factor attached to them, so you should never expect the exact same setup between game sessions.

We generate a lot of interesting special content in the different systems, including the ones that no empire is controlling. This content ranges from debris to ships of unknown origin, that could be friendly or not so friendly... Speaking from personal experience when it comes to the “not so friendly” ships, I recommend all players to scout systems before going there with their science ships to survey a potential future colony. It is not fun having your science ship blown out of existence with your most skilled scientist aboard.

stellaris_dev_diary_03_01_20121005_drone_attack_scienceship.jpg


Next week we will talk about the different FTL types.
 
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At the moment no, but we have had discussions about it. If we were to allow it I imagine that they will be quite rare.

Well, that is too bad, since estimates about double stars say that about 1 out of 2 stars are binary systems. Also about 50% of the systems where we found exoplanets are in a binary system.
So, to be honest, they shouldn't be rare, but very common actually.

EDIT: Just ask your local astronomer if you don't believe me.
 
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I wonder if it is possible to change star to the black hole (or to any other star type) during the game session? For modding events purposes (some evil aliens drop "black matter" bomb into the star).
 
The issue with O stars is that their low life span means there is no time for an interesting system forming around it. So O systems would be mostly boring single body systems

There will be a whole group of soon-to-be astronomy students who will be shocked at university to learn that there is an O-stellar class. "That wasn't in Stellaris!"

But I'd certainly understand the logic in omitting that class
 
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So recommented Procedure: Find system, send fleet, send Scientist or find system sent a Scientist protected by a few Military ships? Like the kolonist in EUIV?
 
Is the map going to be flat (2D) or is it going to have stars up and below the center plane?
Mechanic-wise the galaxy is 2D. All distance calculations etc will use 2D math.
Graphically however we do have some height variation on things to give some sense of depth to the galaxy
 
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Too bad. In real life most stars belong to binary (or larger) star systems.
But unless those stars either are close enoung to practically operate as one star or far enough apart to practically be separate they wont have planets and therefore be pretty uninteresting to this game, so I really don't see the problem.
 
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So recommented Procedure: Find system, send fleet, send Scientist or find system sent a Scientist protected by a few Military ships? Like the kolonist in EUIV?

It depends on how dangerous the threats are. In the early game, it seems very likely that you can run into a threat that could wipe out any guarding fleet you could possibly produce. So I think I would always scout first with small, disposable ships that specialize in running away.
 
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At the moment it is normally 3-10 planets, but it depends on the type of system. This number is being always being tweaked and may change for release. You can mod the files to have how many you like, but I can't promise that everything works if you go up to like 100 planets ;)
Interesting. Maybe you can't answer, would the rest of the game mechanics support a kind of Firefly/Serenity set-up where instead of lots of star system you'd have just a couple of stars with several dozens of planets+moons each? Could you have like a dozen empires on different planets+moons in the same solar system?
 
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Pulsars and neutron stars? Aren't those the same thing, the only difference being that a pulsar has their magnetic pole pointing at us at some point in its rotation?

Also, binary or multi-star systems are very common. Simply ignoring them doesn't feel right. There are a lot of interesting things you can do with them. For example, dwarf stars might be another body in the system, like planets if the primary is sufficiently large. Some systems might have two stars in the center that the planets and other bodies orbit around. Finally, you might has situations where two or more large bodies orbit each other at great enough distances that they each have their own well populated planetary systems.

https://en.wikipedia.org/wiki/Star_system

Here are some examples of each kind of possible binary systems in Stellaris:
Dwarf star as another body in the system (similar to a really big gas giant):
seaRfm7.png

Binary center (mostly the same as a standard system, while orbits would be fine, this would cause havoc on planet's rotations):
PXT8Hnn.png

Multi-star, multi-planet system (I tried to make the stars distant enough that they don't disturb the orbits of the other's planets):
lIAHkyL.png
 
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Awesome! Paradox is amazing as always. ;)
 
This should be fun........looking forward to the next one!
 
The amount of AI empires only affects how many AI controlled empires that are generated from the start, a lot more will spring into existence during your game.

What do you mean by this, how exactly will new civilisations pop up? I'm intrigued!
 
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Seeing you describe different galaxy and start types made me think:

How much/what kind of scientific reserch is done for the game? I feel like scientific accuracy have the same importance as historical accuracy would have in the more traditional PDS games (with respect to certain things ofcourse, you probably understand what I mean).

I feel like many of the best sci fi novels also have putten some effort into the acctual science (e.g. Foundation, Rendezvous with Rama).
 
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