"I do not teach techniques. I teach principles. There are many tenth dan who teach techniques. I teach 0." Soke Masaaki Hatsumi. Understand, Good, Play.
A technique is different from a principle and this is what so many martial arts teach: techniques. Techniques only work within the limited frame they were designed for. If an opponent attacks in a way you don't have a technique for, you will lose. And there is no way to train enough techniques to cover the myriad of ways an attacker may come at you. However, through training principles you are able to learn to adapt to situations as a natural result of your training.
Yes, there are techniques in the Bujinkan, but these are trained to know what the body should be able to physically do. The principles are what are so vital, you can adapt to any situation when training principles.