EMT sissors are also an invaluable accessory when needing to remove a person from bondage in an emergency. They were specifically designed for ambulance crews to cut and remove clothing (including belts and boots) when providing emergency first aid in the field.
Ordinary knives and scissors can easily be used, but EMT scissors are better designed for the purpose. They are made out of stamped, stainless steel sheet metal with a stamped-in ridge for rigidity, and they have plastic handles. The bottom blade is longer than the top blade and there is a section at the end of the bottom blade which has been folded over sideways. Both of these adaptations prevent the scissor points from puncturing the skin and possibly causing further injuries.
They should still be used with care. If a fold of skin gets caught between the blades, you will cut the person and cause a very painful injury. Using the scissors at a perpendicular angle to the skin will reduce the danger of stabbing or slicing a fold. If you place your own hand underneath the rope or clothing to be cut, you will further reduce the possibility of injury.
They are fairly inexpensive, and are readily available at pharmacies.