Chess opening are so complex and theoretical that amateur players will have trouble understanding them. An example is the Perenyi Attack of the Sicilian Defense (see diagram) which yields an immensely complicated and tactical position that even strong players have difficulty handling, and that is beyond the comprehension of most amateurs. Major changes in the rules of chess in the late fifteenth century increased the speed of the game, consequently emphasizing the importance of opening study. Thus, early chess books, such as the 1497 text of Luis Ramirez de Lucena, present opening analysis, as does Pedro Damiano (1512), and Ruy López de
Tactical decision game fictional. If the scenario is based entirely upon a reliable historical narrative, a tactical decision game is also a "decision-forcing case". (Such an exercise may also be called an "historical map problem".) However, if any of the elements in the scenario of a tactical decision game is fictional, then the exercise is a kind of "fictional decision game". In Chapter 14 of "The Prince", Niccolò Machiavelli tells the story of the Greek general Philopoemon, who made extensive use of tactical decision games. “Philopoemon, Prince of the Achaeans, among other praises which writers have bestowed on him, is commended because in