my adventure group from the yawning portal want to go to undermountain. Is there material, maps ect of this huge complex? Desperatly seeking an answer Best bet is to look at classic material available on DMs Guild – https://t.co/Z3SOXZ9KIS#WotCStaff
— Mike Mearls (@mikemearls) January 27, 2018
I also suggest to check 'Expedition to Undermountain' https://t.co/NXEXWLxyWU
will help you a lot with descriptions, details, tactics and development to setup every single encounter.
— Zoltar Sage Advice (@SageAdviceDnD) January 29, 2018