If I buy Dishonored DLC will the game have to update or does it unlock game files?

Logicaly it would add files to DL.

DLC files need to be downloaded (except for some launch day DLCs).

Curious, what game would you say is most like Dishonored? Or whatever... trying to figure out if I would actually like the game or not.

unless they did a very bad thing and locked "on disk" content away from you it should have to download files to add dlc

I own it and it downloads. The Dunwall City Trials DLC is garbage, i wouldn't bother with it. Knife of Dunwall is great, however.

Of course the games will be download.