A Slightly Dumb Question.

[Gut431]

When downloading an expansion for an mmorpg, is it a newer game and you have to redownload all of it or is it a smaller download that adds on to your game?

[Sauron]

...depends on the specific game. In most cases it's just an additional download

[Oshino Shinobu]

It will be an add-on. The original game will stay, though some files may be replaced. 

 

EDIT: If it's an update (a big one), then it may download and replace a lot of the game with new stuff. But for expansions, it's unlikely to redownload original game files. 

[Simba]

When downloading an expansion for an mmorpg, is it a newer game and you have to redownload all of it or is it a smaller download that adds on to your game?

 

What mmorpg are you referring to? For example World of Warcraft downloads the expansion but also replaces texture and model files. This was very apparent when the textures got overhauls in Cataclysm and Warlords of Draenor.