@_Blackstormnever get an answer: does a fighter with improved/superior critical auto-hit on natural 19/18+ or still only with nat 20? If a feature says you scored a critical hit, you hit.
— Jeremy Crawford (@JeremyECrawford) March 31, 2015
@_Blackstormcan u point the phb page?p194 only says nat20 is auto hit AND in addition a crit. Can’t find rules support to your claim. In #dnd5e, a critical HIT is a hit. The fighter's Improved Critical doesn't say you CAN score one. It says you SCORE it.
— Jeremy Crawford (@JeremyECrawford) April 1, 2015