Research
The Research Trees are divided into six sections, four of which are race-specific:
Military
Combat
This tree contains all research items related to the combat aspects of the game, including research projects that unlock new Ship Types and Tactical Structures, or improve existing ships and tactical structures. This tree is specific to each race.
- Advent: Hostility Tree
- TEC: Military Tree
- Vasari: Warfare Tree
Defense
This tree is added in the Sins of a Solar Empire: Entrenchment micro-expansion. Some of the projects were taken from the Combat and Civic trees, in particular Tactical Structures. These projects focus on defense systems and on the starbase. This tree is specific to each race.
- Advent: Security Tree
- TEC: Defense Tree
- Vasari: Fortification Tree
Civilian
Civic
This tree contains all research items related to the civic aspects of the game, including research projects that unlock new Logistics Structures, as well as projects that improve your economy and resource gathering. This tree is specific to each race:
- Advent: Harmony Tree
- TEC: Civilian Tree
- Vasari: Empire Tree
Diplomacy
This tree is added in the Sins of a Solar Empire: Diplomacy micro-expansion. Some of the projects were taken from the Civic tree. These projects focus on diplomatic relations with other players. This tree is specific to each race.
- Advent: Understanding Tree
- TEC: Diplomacy Tree
- Vasari: Manipulation Tree
Fleet Logistics
This tree is the same for all races. It has two sections:
- Capital Ship Commanders: Additional levels of this research project increase the number of Capital Ships you can field. Note that you also have to have sufficient Fleet Supply to support additional capital ships.
- Global Fleet Supply: Additional levels of this research project increase your fleet supply total, which allows you to increase the number of ships you can field.
Artifacts
Main article: Artifacts
This "tree" is the same for all races. You don't actually research anything here, it simply provides an overview of the artifacts you have found, and gives information on the benefits those artifacts provide. Artifacts are discovered by building the Explore Planet improvement, found under the Planetary Improvements section for each planet.