Almost self-explanatory, this file allows in-depth customization of the game's various technology areas. One could alter this file in many ways, ranging from simple modifications in the extents of such areas all the way to introduction of an entirely different technology tree to the game.
First off lets look at what the code is for adding your own techs. You should look at the TechAreas.txt file in the SEV data folder to get an idea of how they work.
Here is an example of the code.
Name := Advanced Military Science Group := Applied Science Category := General Description := The training, study, and improvement of martial practices. Picture Number := 87 Maximum Level := 101 Level Cost := 8000 Start Level := 0 Can Be Removed := True Unique or Racial Tech := False Number Of Requirements := 1 Requirements Evaluation Availability := AND Requirements Evaluation Allows Placement := TRUE Requirements Evaluation Allows Usage := TRUE Requirement 1 Description := Empire must have at least tech level 3 in Military Science. Requirement 1 Formula := Get_Empire_Tech_Level("Military Science") >= 3
Name is the name of the tech that appears in the research page.
Group is what group the tech is a part of. You can change this to whatever you want and the name will show up on the right hand side of the research page. This keeps the techs organized so you can filter out which ones you want to see in game. At the moment Im unsure of what category does.
Description does what it says, Provides a description of the tech.
Picture Number is the picture the tech uses for its little icon. The tech pictures sheet can be found in Space Empires V\Pictures\UI\Bmp_TechIcons.bmp. It is a 24 bit bitmap of all of the techs. Each square is 36 by 36 pixels. The number tells the game which picture square to use. It counts from the top left to the top right like reading a book. You can change the dimensions of this picture sheet to any size you want as long as the little squares can fit in the sheet.
Maximum Level is the max amount of levels you can research.
Level Cost is used to determine the cost of each level of the technology. The exact formula used depends on the tech cost setting chosen at game start. You can view (and mod) the formulas in Formulas.txt.
Start Level is self explanatory, it is the starting level of the tech.
Can Be Removed is a holdover from SE3 and SE4, where you could remove tech areas from existence in a new game. Such functionality was not added to SE5, however.
Unique or Racial Tech determines if the tech is unique, like you get from ruins, or racial, like picking crystallurgy. I believe that it references what is in the RacialTraits.txt file.
Number of Requirements is the number of requirements that must be satisfied to unlock this tech for research. Below this are the formulas and text description of the requirements. Requirements can be minimum levels of other tech areas, maximum levels (eg: for exclusive tech areas), racial traits, and possibly other fancy things modders will come up with in the future.
If you are adding new tech areas in TechAreas.txt, you cannot use saved empires or saved game setups that were created before the change. You must create new empire files or a new game setup for the changes to register. Changes to TechAreas.txt will not affect quick start games.