Board Thread:General Discussion/@comment-6122870-20140318163542/@comment-16674955-20140914145949

You can't compare the tower in ToG/TUS and Aincrad. Only the concepts of "tower" and "floors" are similar and this concept have been around for a very, very, very long time. None of them copied each other... and if you read SAO novel or watched the anime you'd realise they're completely different apart from that.

They are both awesome as well though.