Board Thread:Wiki Discussion/@comment-4511886-20150401082635/@comment-26215013-20150401214133

I would say that semi-optional bosses is an extremely vague and mostly personal descriptor of certain bosses. If they can be skipped in the vanilla game without exploits and without a problem then they're optional, whereast if you can't get around them without problems or exploits they are required. I don't feel like there is any real grey area here, least of all enough to argue semi-optionality of bosses.