Prior to the twentieth century, many board games served a dual purpose, simultaneously entertaining and educating players. The Checkered Game of Life and Mansion of Happiness, for instance, incorporated moral values into game play, rewarding virtue and condemning vice. Though by the 1900s game manufacturers began to emphasize entertainment over education, instructional games meant to make learning fun have persisted. The board game Strangers and Dangers first appeared in 1985, designed by three law enforcement professionals. The game teaches children the basic rules of personal safety, portraying "real life experiences in an enjoyable and non-threatening manner."