Moon Lovers: Scarlet Heart Ryeo (Korean: 달의 연인 - 보보경심 려; Hanja: 달의戀人－步步驚心 麗; RR: Dar-ui yeon-in - Bobogyeongsim ryeo; MR: Tar-ŭi yŏnin - Popokyŏngsim ryŏ) is a South Korean television series based on the Chinese novel Bu Bu Jing Xin by Tong Hua. It aired from August 29, 2016 to November 1, 2016 on SBS every Monday and Tuesday at 22:00 (KST) for 20 episodes.
Despite its ensemble cast, extensive publicity and US$13 million production budget, the series received criticisms for its screenplay, direction and performances. It did, however, perform well overseas. The drama has reportedly been sold for more than $400,000 per episode to the Chinese broadcasting station YouKu, totaling over $8 million and thus became the most expensive K-drama ever sold. The record was beaten a few months later by Man to Man.