A recent FAQ was published aiming to answer several common questions associate with The Ipynsh Sanctuary set to arrive later this month. If you’re unaware, The Ipnysh Sanctuary update will contain a dungeon, The Immortal Warden’s Armor, Mistsong Banquet Updates, Balance Changes, God's Authority Skills, New Arena Shop Mount, and more. The dungeon itself is meant for parties of 3-5 players.
Perhaps most importantly, you will need to own Garden of the Gods in order to access The Ipnysh Sanctuary,
“Yes, you will need to own one of the Garden of the Gods packages to participate in the newest Dungeons, utilize god powers, and more.”
As for what happens if you don’t own the expansion and try to queue for the dungeon,
“The requirement to join the Ipnysh Sanctuary is being an owner of the Garden of the Gods Expansion pack. Attempting to join the Dungeon without the Garden of the God Expansion pack will present an error message in the middle of your screen.”
You can catch up on the whole FAQ here.