In SoaSE, there is a dev version of the base game you can access, which lets you pretty much do anything ingame (correct me if I'm wrong). SotP is an example of a mod that also has a dev version to it (NOTE: I am not talking about the PT build, I'm talking about the public build that is released right now) which you can access with a few "easy" steps.
Step 1.
Locate and enter
C:\Users\NAMEHERE\Documents\My Games\Ironclad Games\Sins of a Solar Empire Rebellion.
Step 2.
Copy files from "Mods-Rebellion v1.82" into "Mods-Rebellion v1.82 Dev". If it asks, replace the enabledmods.txt in the folder with the newer one. Then go back to main folder.
Step 2.5
You need to launch the DEV version first before doing Step 3. You can find the .exe file at C:\Program Files (x86)\Steam\steamapps\common\Sins of a Solar Empire Rebellion. Open the "Sin of a Solar Empire Rebellion Dev.exe" and close with task manager.
Step 3.
Go to the "Setting" folder and open "rebellion.user.setting" with notepad.
Step 4.
Find "Show Errors" (Press ctrl+f and search it. It's much faster)and change TRUE to FALSE.
Step 5.
Locate and enter
C:\Program Files (x86)\Steam\steamapps\common\Sins of a Solar Empire Rebellion.
Step 6.
Find the executable file "Sins of a Solar Empire Rebellion Dev.exe". Open it to start running dev version. (NOTE: If window appears showing errors/breaks, open task manager (ctrl+shift+esc) and force close the window. Then repeat Step 3-6.)
Step 7.
Enter a match and press "control + shift + period (.).
Step 8.
Mess around and have fun!
This guide is for newcomers and anyone who doesn't know about the Dev version of the game. If you would like to critisize about "OMG I ALREDY NEW TIS Y U PUT DIS ON HERE11!11111!!1" then please don't reply. Thank you!