Mods and Savegames

Is it possible to make mods that effect savegames / games already in progress?

Or is your modset fixed once you start a game, with no possibility to extend it?

 

I created a mod that changes the cost of a given tech. I can save a game and add another tech to the mod (without changing mod name, .modinfo) and it is recognized when I load the game again. Not sure that's what you are asking but hopefully it helps.

[edit]I should say that if you already started the game, I don't think so. But I do think you could created a basic 'blank' mod like I did and add to it after you have started the game.