Hey Mike! With Barbarian Rage, if they were to take 1 damage – would it reduce the damage dealt to zero? [1/2]and with Heavy Armor Master feat, can that reduce damage to zero, or to a minimum of 1? Your input would be very appreciated! [2/2]

— Dan Miller (@Chillfast001) July 16, 2017

I think damage is always minimum 1, but no book here – check under damage in phb, otherwise apply rules for rounding as normal

— Mike Mearls (@mikemearls) July 16, 2017