Although personal combat arts were undoubtedly a component of traditional ninjutsu, they were by no means the principal focus of the art. More significantly, resorting to fighting was a clear indicator that the ninja had failed in ninjutsu's primary tenets of operating invisibly and undetected. The disproportionate emphasis placed on taijutsu today could be interpreted as an expectation of failure in one's objectives; one that will necessitate an exceptional degree of fighting ability to recover from. The historical ninja, perhaps more prudent than today's ninjutsu aficionados, considered it wiser to dedicate training time to disciplines that might prevent failure, such as those addressed in this book. In the chapters that follow, we will introduce some of the many requisite ninjutsu skills that are overlooked, ignored, and noticeably missing from modern training today.