No you can not
no it is on online mode
Yes you can play them on most game types but they will not be able to play undead overrun with you unless they have the undead nightmare game/dlc as well.
You can't play coop on Red Dead Redemption or Undead Nightmare.
its on Undead Nightmare
No, if you buy the one for 20 dollars that is undead nightmare but not the original. The only way to get both is buy the Original Red Dead Redemption and then buy the Undead Nightmare add-on
You cant.
Only if you want to download the game, if you buy the undead nightmare disc the no you don't need the original red dead redemption.
Well, you can get Undead Nightmare into the Red Dead Redemption disc if you download it from the PlayStation Store.
You have to get in a fight with them.
There are two, Red Dead Revolver, and Red Dead Redemption and Red Dead Redemption Undead Nightmare
No it is a stand alone disc that allows you to play the Undead Nightmare DLC without Red Dead Redemption
I would say Undead Nightmare is a DLC because you die in The 1st Red Dead Redemption...