Don’t Gamble with the Future of a Nation Unless You’re a Royal Gambler
The Royal Gambler (2016); 24 episodes; streaming on Viki.

This historical K-drama is about King Yeongjo, and fictionalizes the 1728 Musin Rebellion (also referred to as Yi In-jwa’s Rebellion).
Baek Dae-Gil (played by Jang Keun-Suk) and King Yeongjo (played by Yeo Jin-Goo) are brothers. They don’t know until their mother tells them. Brothers? The king thinks that means that his brother might connive to take his place on the throne. His brother tells him he has no interest in the throne. However, he can’t control what the people think or what the king thinks. He just knows he’s not interested in being king.
King Yeongjo’s mother tells him they should always support each other as brothers because she knows who their real enemy is. The real enemy is a man named Lee In-Jwa (played by Jeon Kwang-Leol). He wants to lead a rebellion and he’s a nasty piece of work!
Just as an example Lee In-Jwa’s dealings show how shrewd, cunning, and manipulative he was. He knew that King Sookjon coveted a particular woman, but that woman was married and pregnant. That woman’s husband was a terrible gambler. Lee In-Jwa persuades the king to visit the gambling den and make the man bet his wife. If he lost the game the king would take his wife. The man loses and the woman becomes the king’s woman. She tells him about the pregnancy but he accepts it because he is so besotted. The child she bears is Baek Dae-Gil and she sneaks him out of the palace, saying that he died, and gives him to his father (her previous husband) to raise. The people in the palace will harm him.
Lee In-Jwa likes to use gambling as his means to get anything and everything he wants. He says what he does is for the people of Joseon. But that’s debatable. Baek Dae-Gil is known to be the best gambler in all of Joseon and he wants to thwart Lee In-Jwa’s efforts to accomplish anything. When he meets his brother, King Yeongjo, he remembers what their mother told them. They use gambling and work together to STOP Lee In-Jwa.