Ninpo (忍法 Ninpou; Ninja Arts) are the spiritual and mental arts of the Ninja, performed through techniques. It is a spiritual power that only highly trained Ninja can use. These arts are so powerful that an inexperienced Ninja would be overcome by their own spell. Some of these techniques were said to be passed on to the Ninja by Tengu.
- When performing a Ninpō technique in Ninja Gaiden 2, Siddham characters appears on screen. Siddham script is an old alphasyllabary used to write Sanskrit language and is used today in Japanese Tantric Buddhism for mystical purposes. Japanese Tantric Buddhism is also closely related to ninjas.