Humor is an important technique in storytelling and communication. It enhances the game experience by fostering player engagement, creating emotional balance, and building interesting characters. Given its inherently playful nature, games are well-suited for delivering humor. However, designing humor in games is complex and challenging, as players are both the recipients and contributors to the humor. Despite advances in theoretical analysis and case studies of humor in games, there is still a lack of comprehensive reviews and classifications of humor techniques specific to game design. This paper provides a classification that covers a wide range of humor techniques. Additionally, we discuss how to apply these humor techniques to storytelling, game mechanics, and game artifacts. Our goal is to offer a systematic review that assists game designers in methodically incorporating humor into games.