"In this new Unearthed Arcana for the One D&D rules system, we explore material designed for the next version of the Player’s Handbook. This playtest document presents the rules on the Cleric class, it's Life Domain subclass, as well as revised Species rules for the Ardling, the Dragonborn, and the Goliath. You will also find a current glossary of new or revised meanings for game terms."
Claim Unearthed Arcana now! - D&D Beyond
www.dndbeyond.com
WotC's Jeremey Crawford discusses the playtest document in the video below.