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 wargame on the then-ongoing Cold War, called "Red Star/White Star: Tactical Combat in Western Europe in the 1970s". While the game was successful, Dunnigan was disappointed with it, citing difficulties in realistically portraying tactical combat in a tabletop board game. Dunnigan tried to take tactical games into a new direction in 1973 with "KampfPanzer" and "Desert War", which featured simultaneous movement, expanding on an optional rule for PanzerBlitz. Unfortunately, the quest for greater realism was having a price in complexity and "bookkeeping", or recording of moves on paper. Nonetheless, other tactical games on a man to man level were released with