Aurora C#: How to Create Custom Starting Systems and Races

Are you tired of the same old Sol start? Maybe you want to play a lost colony of humanity in some far away star system. Maybe you think it would be awesome to play an alien species. Did you even know that you can do that in Aurora? If you’re a new player you might not. The game doesn’t really advertise the option. Back in VB6 there was a setting on the New Game screen. It took you to a very intimidating window that was only documented in a few scattered forum posts. I was always too afraid to use it. Even that setting is gone from C#. I’ve seen a number of players struggling to figure this out and some even suggesting that it’s not implemented yet.

I’m here to tell you that you can play a custom game right now and it’s easy!

First, start by setting up a new game as normal. Most of the settings should be applicable to a custom start. You can choose to use Known Stars or random ones. If you use Known Stars be aware that Minimum and Maximum NPR distance is still calculated from Sol so if you start in that distance band you may end up with aliens in your backyard.

Make sure that you leave the number of player races at 1. This is important because you cannot start the game with zero player races.

When the “Create New Race” screen pops up don’t bother changing anything. You will not be playing this race so the Empire Name and population don’t matter. Just hit “Create Race” to continue. The game will proceed to generate the starting systems and load into Sol.

Now, you want to turn on the Spacemaster Mode. That’s the button on the top right of the screen that looks like a crystal ball. If you aren’t familiar with Spacemaster Mode, it gives you godlike powers over the universe of Aurora. You can use it to cheat mercilessly or to gently tailor the game to your narrative. Sometimes those things look very similar. Whether you abuse the SpaceMaster mode (it’s a single player game, do what you want) or not it’s still a very useful tool to learn. Today, we are going to use it to create a custom star system.

When you click it the crystal ball should light up to indicate that Spacemaster Mode is on. Now you want to select “Open System View” from the menu bar. That’s the view that shows you a table of all the planets in your systems.

With Spacemaster Mode on you will see a whole bunch of new buttons in the lower right corner of the screen. These are the system editing buttons. You can do a lot of interesting things with these buttons. If you want to meticulously create a whole system and every planet in it from scratch you can do that. There is a good explanation of how all the options work in the Aurora Changes thread under Star System Design but you don’t need to understand all that now. We are going to let Aurora create a random system and then tweak it.

Click the “Create System” button to generate a random system.

If you are playing Known Stars you will be given a window to select your starting location from a list of nearby stars. Scientists believe that G or K type stars are more likely to have intelligent life so if that’s important to your fiction choose one of those. Aurora can generate near habitable planets around any star so feel free to experiment. For the purpose of this tutorial I am going to choose Tau Ceti, a G8V star relatively close to Sol.

It may take a few tries to get a random system that you like. It doesn’t need to have a habitable planet but at least one low colony cost Terrestrial planet (cyan) is a helpful starting point if you don’t want to spend a ton of time system sculpting. Remember that Sol is a very dense system with a lot of planets and asteroids, including several low colony cost easily terraformable planets like Luna and Mars. If your new system has only a handful of planets, you will have a more difficult start and will need to expand more quickly to other systems for mining and colonizing. It’s not cheating to reroll until you get several cyan planets or a big asteroid field if you want a starting setup that’s comparable to the default.

If your system is too sparse or otherwise not to your liking, you can regenerate it by clicking “Delete System” and “Create System” again.

I’m going to use this system as my starting point:

System View of Tau Ceti with several planets listed, described below

It’s only got a few rocky planets but lots of gas giants and small moons so hopefully that will satisfy our early need for minerals. The inner planets are not very habitable right now. The first planet has a temperature of 148 degrees celsius and the second planet is a tiny frozen chunk of rock. That’s okay!

If you want to play a non-human race that evolved on one of these planets, you can actually do that right now. Maybe your race evolved on the cold airless surface of Tau Ceti II. Select the planet and click “Create Race” from the set of buttons on the lower right.

This will pop up the default race creation window so you can configure the starting population and industry of the new race. Notice in the bottom left panel that the Ideal Gravity, Temperature and Oxygen pressure are quite different from human norms!

A Custom Race with an Ideal Gravity of 0.06 G, Ideal Temperature of -64.16 C and Oxygen Requirement of 0

These new non-human parameters will be used to calculate the colony cost of all worlds for this race which is also going to change the difficulty of the game. This species doesn’t even need to breathe, so forget terraforming. They can plop down a colony on small cold airless rocks like asteroids without too much effort but the max pop will always be small. Maybe that’s what you want in which case you can skip the next section of the tutorial entirely.

Disclaimer: I have not actually played this race for more than a few construction cycles. The game didn’t crash or anything but I make no guarantees that you won’t run into any problems with a race this weird. It’s probably best to create something a bit more human-like but feel free to try it out and let us know how it goes.

So what if you want to play humans? Or a more traditional oxygen breathing race? That’s also pretty straightforward. We just need to modify one of the planets to make it suitable.

I am going to start by selecting the Terrestrial planet and clicking the “Modify Body” button in the lower right panel of the System View.

The Modify Body screen allows you to edit properties of the planet and its atmosphere

There is a lot going on in this screen. You may not even realize the values in the upper left panel are editable but they are and this is how we sculpt planets.

First thing to notice is that Tau Ceti I is Tide Locked. That happens because the planet is too close to the star. Tide Lock is when one side of the planet always faces the star and the other always faces away. That means one side of the planet is always in daylight and very hot, while the other is always in darkness and very cold. There are several theories about how this would impact habitability but for the purposes of Aurora it severely reduces the maximum population of the planet.

We probably don’t want that for our home world so I will start by moving the first planet farther from the star. This will also lower the temperature. There is plenty of room between the first and second planets so I started by doubling the random Distance to 102 million kilometers. That wasn’t quite enough so I tried a few different values and ended up with 115 million.

The next value on the screen is Diameter in kilometers. Earth has a diameter of 12,742 kilometers. This value also impacts the maximum population. You probably want a decent sized home world so I doubled this value as well to get 9200. Still smaller than Earth but a reasonable number. Maybe you want your planet to be a Super Earth. In that case make it larger.

Next is Hydro Extent (0-100). This value is the percentage of the planet’s surface that is covered in water. On Earth, that number is 76. If you want your planet to be a desert, you can set it much lower to achieve that. Or maybe you want a water world where people live on scattered islands. You can do that too. Too much or too little water will impact the maximum population so be aware of that as you experiment. I’m going to arbitrarily set this planet to 60.

If your planet is too hot the water will boil off and disappear. If your Hydro Extent keeps getting set back to 0 that’s probably why. In that case you need to move the planet farther from the star or do something else to cool it before adding water.

The fourth value is Albedo, the measure of the amount of light reflected by a surface. Darker surfaces absorb light and heat up more while whiter surfaces reflect light and are cooler. Our random planet’s high albedo is contributing to the blistering surface temperature so I will lower this. 1 is a reasonable default setting. You can look up how the Hydro Extent impacts albedo if you really want to be scientific but for gameplay purposes you can set this to any arbitrary value to get the temperature you want. Once an atmosphere has been added to the planet we can come back and tweak this to make any final adjustments.

The last important value is Density. The size of the planet in comparison to Earth and the density will determine the gravity in Gs. Aurora is very generous with human gravity tolerances so this isn’t too important but if your planet is very large or very small you might need to tweak it. If you want a specific gravity you can calculate the necessary density to achieve that. Let’s say we want the gravity of our homeworld to be 0.7G. Take the diameter of the planet (9200 in my case) and divide it by Earth’s diameter (12742). That gives me ~0.722. Then divide the target gravity by that value to get the density. (0.7 / 0.722 = 0.97). So I will set the density of my planet to 0.97.

Next there is a field for Day Length. I don’t think this actually does anything in the game but I like to set it to a reasonable value anyway.

Currently the settings look like this. Select “Update Body” to apply them.

The Modify Body window with the above settings entered

Back on the System View Tau Ceti is starting to look a little more habitable, but there is still one thing missing. It doesn’t have an atmosphere! If you are designing your own planet you want the temperature to be colder than desired at this point. For an Earth-like final temperature being a little negative now is good because the atmosphere will retain heat and cause the surface temperature to increase significantly. If your planet has a positive temperature you might want to increase the distance a bit more before moving on.

Go back to the Modify Body screen. The bottom left panel will allow you to add various gasses to the atmosphere. If you have done any Terraforming in Aurora this should be familiar. Choose a gas, enter a value and click Set to apply it. Earth’s atmosphere is 78% nitrogen and 21% oxygen so if you’re making a planet for humans use that as the baseline. In Aurora, oxygen becomes toxic over 30% so you want to keep it lower than that.

Let’s start with 0.8 nitrogen and 0.2 oxygen to keep things simple. Just below the atmosphere this panel also tells you the new Surface Temperature of the planet. Mine has increased from -20 to 5.35 Celsius. If you want the planet warmer, you can increase the thickness of the atmosphere while keeping similar proportions. You could also go back to the top panel and tweak the albedo a little.

The Atmosphere Panel of the Modify Body Window with 0.8 atms of Nitrogen and 0.2 atms of Oxygen

Now close the “Modify Body” window and you should see a habitable planet in the system view.

The System View with Tau Ceti I as a 0 Colony Cost habitable planet with 60% liquid and a nitrogen/oxygen atmosphere. Surface temperature of 5.4 C

Feel free to play with the planet a bit more. See what happens if you add some different gasses to the atmosphere. Change the default terrain. Make it bigger or smaller or whatever you like. It’s your home world.

When you are satisfied select the planet and choose “Create Race” in the lower right of the System View.

The game will default to creating a new species that is perfectly suited to the selected planet just like it did before. If you would want to play default humans, you need to go up to the top right of the “Create New Race” window, select the Species dropdown and choose Human. You should see the image and ideal environment parameters change to the defaults.

Now you can go ahead and set up the starting conditions, name, flag, population size and industry for your empire just like you would when creating a new game. When you’re done hit “Create New Race” at the bottom of the window.

Now you have two races. The default “Player Race” and the new race. The last thing we want to do is delete the original player race. You could also decide to play both races. Aurora will let you do that. You could play humans vs aliens starting in totally different star systems. You can toggle between races using the dropdowns on various screens. There is even a handy checkbox in the tactical map “Display” tab called “All Windows Linked to Race” which will update all your open windows whenever you swap over.

We’re not going to get into that now though.

To delete the default race open the “Race Information” screen in the menu bar. It’s the button that looks like the British flag. From the dropdown in the top left make sure that “Player Race” is selected and then click the “Delete Race” button at the bottom of the window. Click yes on the confirmation prompts.

The title bar of the window should now show the name of your new race. Go ahead and disable the SpaceMaster mode by clicking the crystal ball icon again. The light will turn off.

That’s it. You should be looking at your new system and ready to play the game.

The Tactical Map showing my custom Tau Ceti system

I have played multiple games in C# with default humans in custom systems for 30+ years using this method so I can attest that it’s very stable and works well. I have not tried it with alien species but I would love to hear about your experiences if you do.