Board Thread:Mortal Kombat (Alternate Timeline)/@comment-26050254-20161107025545/@comment-21005855-20170324143934

@Fusionx: That's a part of the reasons. Another reason is when there is an illegal invasion.

I've always assumed that every realm that has merged into Outworld has been done according to the rules of Mortal Kombat. It's either that or the rules were created to put a stop to the constant invasions/merging of realms.

If the question is why they allow invasions in general then I would say that it's because they won't do anything about it until there's a merge going to happen.