You're friend would enter your stronghold, help you prepare, and then the both, or 4 of you would fend off waves of enemies from the stronghold. Rewards could possibly include upgrading your stronghold or something else.
It could either user your stronghold from the main story ( I like), or just have a stronghold that you defend (not necessarily in main game).
I really like this idea since it doesn't change the single player at all and it gives us an opportunity to play with our friends!
Feel free to comment on whether you like it or not, or if you have suggestions.
Edited by theADOLESCENT, 16 October 2012 - 06:15 AM.