When you create your empire you'll have the ability to play as a human, or create a custom species. Each species has 13 affinities. Affinities are attributes that determine a specie's particular characteristics. It makes them good or bad at various types of activities.
Each empire is only allowed 45 total points when first created and they must all be assigned before your empire creation is complete. It is possible however later on to change your species affinities later by going to the species tab of your profile and paying 100 Essentia.
You can also get up to an additional 30 affinity points through the Genetics Lab which can be built when you reach University level 20 or with a level 1 Gene lab plan which you can obtain via Trade or through the Mission Command.
Note that you can't get to maximum in every affinity. You can increase your affinities to 75 out of a total of 84. So when you start playing with the Genetics Lab, choose your affinites wisely.
As of server release 3.0822, redefine species is available at University level 30. WARNING: Drops attribute total to 45. Redefine is available from University Levels 1-19 and Level 30. In all cases, you will have 45 points to play with and lose any genetic grafts you may have done. This allows you to redo your species if you feel you want to start again.
When you redefine your species, you must take into account any orbits that your species currently inhabits for any reason, even if due to terraforming.
There are 13 total affinities. Each affinity has special characteristics that will define how suited the species is to various tasks. However, the exact modifiers applied, and what they are applied to, are a secret, and something for you to figure out as you play the game. Almost without exception, each affinity affects obvious things, and not so obvious things about the game.
With the exception of habitable orbits, each affinity is a range between 1 and 7, where 1 is worst and 7 is best. Habitable orbits can be 1 through 7 and everything in between if you want. Here is a brief description of each affinity:
Habitable Orbits - In the Expanse each star may have up to 7 bodies orbiting it. The closer orbits are very hot and the further orbits are very cold. This affinity affects the climates that are survivable by a species.
Note: Orbits 2-6 tend to be the most advantageous orbits to colonize due to having a wider variety of food available in those orbits. Orbit 3 has the greatest number of food types available. Having orbits 1-7 can be advantageous if you intend to colonize every planet in a single system, however if you intend to spread out more into other systems you may do better to limit your species to a narrower range.
Manufacturing - Controls special advantages related to manufactured goods. This affinty allows you to build ships cheaper, upgrade buildings more quickly, and boosts the production of 2nd tier food types, and resources that come from the processing of waste.
Deception - Controls special advantages in the training of spies. This affinity will control things like the rate you build spies, the rate your spies are able to perform actions, etc. It also affects the stealth level of your ships.
Research - Controls special advantages in technological advancement. This will allow you to create buildings cheaper. However it doesn't affect the cost of repairing buildings. Upgrades take your research affinity into account to discount the upgrade cost. Downgrades do not and neither do repairs.
Note: This affinity is one that is fairly easy to get around not having it at a high level, though it will take longer to save up all the resources you need to build some upgrades but frequently many empires end up finding they have an excess of resources and the higher costs can be gotten around by having more storage.
Note: Having this affinity at level 7 becomes very important especially at the upper university levels as it allows especially for the faster production of Excavators which in turn leads to a greater production in glyphs which allow for the construction of the most powerful buildings in the game.
Farming - Controls special advantages in food production. Higher levels in this affintiy will give you more food over time from things that produce food and also increases the food storage capacity of buildings capable of doing so.
Mining - Controls special advantages in the harvesting of ore. Higher levels in this affintiy will give you more ore over time from things that produce ore and also increases the ore storage capacity of buildings capable of doing so.
Science - Controls special advantages in the application of science to technology and energy. Higher levels in this affinity will give you more energy over time from things that produce energy and also increases the energy storage capacity of buildings capable of doing so. It also affects energy costs for ships and buildings that consume energy. This also affects the speed of your ships.
Environmental - Controls special advantages in the management of waste and water. Higher levels in this affinity will give you more water and less waste over time from things that produce water and waste. It also increases the water storage capacity of buildings capable of doing so.
Note: This is an affinity that is easier to get around not having at a high level. It will mean you will have lower happiness production which is key to colonizing more planets but it just means that it will take a little longer until you can launch your next colony ship.
Trade - Controls special advantages in all things related to barter and trade. This will affect the cost and speed of trade, the cargo hold size of ships, and the size of trades you are able to post in the Subspace Transporter.
Note: This affinity is one that there is little compensating for having at a low level. This is even true for empires interested in battle capacity as it affects the hold size of of Scow which is a key ship in reducing the happiness of a colony.
Growth - Controls special advantages in the colonization of worlds. Higher levels of this affinity will improve the rate and cost of colonizing other planets. It also makes it easier to complete the spy mission Insurection.
Note: This affinity is one that doesn't need to be maxed out though it is useful.
Humans are the absolute average species. They have only the #3 orbit and have 4 assigned to all others.
If you choose to create your own species you will get 45 points to spread acorss the 13 different affinities. The custom race you create will be unique in the expanse by name. No one else will be allowed to play it, or know what affinities you have selected. That is, unless one of their spies captures one of your spies and they use the Gene Lab to examine your DNA or they look up your species in the ancient Library of Jith.