lol @ the box with nothing inside idea, pass the parcell with a tictac inside anybody?
Yes this is genuine concern but its not a Steam issue, it is a development one, will DLC be taken into consideration and development designed so that all DLC difference won't end up segregating the players. I.e will player A with no DLC be able to play player B with full DLC, I hope so is my answer. I hope the development is done to an acceptable standard. I'm not so much concerned that someone with DLC will have an advantage over someone without, hopefully this is too taken into consideration and that all civ's released be it in vanilla or DLC are balanced to not be overpowered. I'm sure it will be. But if downloading DLC will cause you to have less people to play against, this is not good at all.
Hopefully we will get a confirmation at some point that DLC will not result in combaitability issues.
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As for the topic creators point, no Bablyon will not be shipped in any box version at retail stores, the only way that you will be able to obtain it on release will be via Steam DE edition. Its likely however that it will be released again via DLC or Expansion pack to generate more profits and then everyone will have the chance to get it even if they brought the box edition. So yes it is likely that if you buy the box retail edition standard or collectors, eventually via a small DLC which wont take up much of your monthy allowance you can get it. Though nothing has been set in stone.
Hope I was helpful.