You can swap back and forth between the game and for example an SQL fie and make edits to it, but none of these edits will be implemented within the game's database until you save and then reload that saved game. Game Data that is in the database is locked for the duration of that session of a game. You have to exit the game you are playing and at least return to the main menu and then reload before any alterations can be made to the game's database. Certain types of game data should never be altered once a game is started, however. You should not add for example a new unit to the game once you have started a game because this can cause desynch issues between the ID #'s assigned to the units in the database when the game was saved, and the new set of ID #'s and etcetera when the saved game is reloaded with an altered database. This sort of thing is also the root cause of why updates to mods can often make a saved game unrecoverable -- the process of updating the mod can cause a user's list of mods to load in a different order than when the game was first created, and now the assignments of row #s and Id #'s is different simply because the total set of mods currently being run load in a different order. The basic rule here is that you should never add or remove anything that must be registered within gametable <Types>, and you should never alter the order mods load when they are adding new elements or adjusting elements of the game that must be registered in table <Types>. Unfortunately Steam don't pay any attention whatever to this rule. Firaxis does not control how mod updates are handled for a user -- Steam does. Lua User Interface files and "context" XML files can be edited in realtime and the changes will be reflected in the correct UI panel or poop up. But this is not gameplay data, this is display code for the interface between the human user and the game.