[Includes 4 maps and 3 figures] This latest Leavenworth Paper is a case study in the wartime evolution of tactical doctrine. Previous publications of the Combat Studies Institute have examined the peacetime development of doctrine and have increased our knowledge of how doctrine has been applied. With the publication of Captain Lupfer’s study, “The Dynamics of Doctrine,” the Combat Studies Institute adds another dimension to the history of the processes of doctrinal change. Besides providing a summary of German infantry tactics of the First World War, this study offers insights into the crucial role of leadership in facilitating doctrinal change during battle. It once again reminds us that success in war demands extensive and vigorous training calculated to insure that field commanders understand and apply sound tactical Principles as guidelines for action and not as a substitute for good judgment. It points out the need for a timely effort in collecting and evaluating doctrinal lessons from battlefield experience. Finally, this study reminds us of yet another fundamental lesson from the past-that tendencies toward accepting the battlefield as a routine can be a deadly error. Altering previously accepted tactics in the middle of a struggle, as the author points out, is a very urgent and serious matter. As members of the Profession of Arms, we must be sensitive to the demands of change, visionary in our examination of their implications, and creative in our adaptation of combat organizations, tactics, and techniques.