Hi everybody. First I was looking to find out how to even play siege but I think I figured it out if it is indeed under co-op arena (though I haven't seen the option and I can never find a game with just DLC, so far.
I also bought it partially to get rid of the message that keeps popping up before i start the game, which states "we see that you don't have a new map pack. whould you like to visit the playstation store? (Y/N)". Yet that message still comes up! I definitely need help and I'd greatly appreciate it.
Edit: Thanks Hosnor. Coincidentally, I found the answer to my question in another thread at the same time that you posted.
ok so in siege you want to stay in the circle . unless all 3 members are in the cirle (it will be green) no one gets points for kills so dont kill enemies until your all in the circle (unless you have to).
Yes its under co op arena it will come up very often when in the voting screen. Also you will need to go to your profile and put dlc yes on or it says something like that but its important to do that to get siege to come up.