User blog comment:Serza5/"It's free, why can't I do that?"/@comment-204.126.10.232-20141211174850/@comment-3076833-20141211225851

Game mods as stated are just external bits of code (and perhaps models and textures etc) that's placed on top of a game and are distrubted by themselves. For instance a mod for Minecraft where you can get...say a battle axe is a bit of code that allows you to have an axe in the game, but doesn't come with the full game in the download. This is legal because it doesn't use any code that's inside the game (only references it to make it fit in the game). Mods are only illegal if it comes with the entire game in it's distribution.