Say I want to put a weapon model I just made into a game I play, (as a mod) what would I need to do in blender besides the modeling and texturing? Will I have to set the reflectiveness of the object? If I didn’t, would the object be dark in the game? What else should I do before I consider my model done?
I don’t think I could help you until you told us what game.
This really isn’t a Blender modeling question. Ask in the Other Software forum ( or maybe one of the Game Engine forums, but don’t tell them I sent you), and be sure to mention the name of the game in the thread title, so anyone with experience with that game will give it a look-see. Generally each game has different requirements. Your best bet, really, is the mod forum for the particular game, rather than here.
Try to import it into the game and then see for yourself. Often, the specularity map is painted in the alpha channel of the normal map in .dds format, which is commonly used for games.