Dynasty Warriors 4 (Shin Sangokumusou 3 in Japan) is a hack and slash video game and the fourth installment in the popular Dynasty Warriors series. Dynasty Warriors 4 was developed by Omega Force and published by Koei. The game is available on PlayStation 2 (PS2) and Xbox and is based on a series of books called Romance of the Three Kingdoms, written by Luo Guanzhong. As the series has progressed, it has strayed further from the actual plot of Romance of the Three Kingdoms but instead has given the user more input on how the storyline progresses. When it was released in Japan as Shin Sangokumusou 3, it topped the sales charts, sold over one million copies within nine days, and received an average of 78 out of 100 on Metacritics reviews.