Other games may use UE3 but I think it is at least 10 years old and UE4 is newer. Since there is a newer version out I don't get why they didn't use that.
To those that bought this game already, Beta Wave 7 will be out at the end of this week and you will be able to play it.
My understanding is that devs do not buy UE, the makers of UE instead get a certain amount of money though from each copy of the game sold.
Cold be more mature modding tools that they use to make the game, less resource intensive so they are able to add all the features that they are wanting, maybe just not experienced enough with UE4, who knows.
If you want your game to be playable by the entire PC Master Race, then you use an old engine.. that way the guy who has not upgraded in 10 years can still play it..
Ah I see. I wasn't sure how any of that worked but that makes sense. Also what Ked said makes a lot of sense too.
