Summons
A powerful jutsu, Ninpo Kuchiyose allows a ninja to summon animals, objects and the dead to fight on their behalf. The ninja normally signs a blood contract with the animal species, which allows them to summon different size and skill levels of creature. The ability to summon more advanced animals largely depends upon the amount of chakra the ninja can muster to perform the jutsu. By signing this contract, the creatures themselves can also reverse summon the contract signer to their location.
To summon the creature the ninja will wipe blood on the hand, perform the necessary handseals and then touch their hand to the ground or another object. Though it appears that as long as significant pressure is placed against the blood in some form, the summon will be complete. There can be variations to the summoning steps, some ninja like Temari will wipe blood on her fan, then by swinging the fan the animal is summoned. Other ninja like Orochimaru wipe the blood across a snake tattoo on their arm first, then touch the ground.
Obtaining A Summon
To obtain a summon from a Sage or Original Summoner, their roleplaying characters must meet and the sage would have a scroll of who his or her students of the summons are. The shinobi who wants to learn the summon would sign the scroll with blood. The sage may give out a test or anything of some sort for the shinobi to do so that they get the summoning. That is, if they passed the Sage's test. The only shinobi who are allowed to have a summoning are Genin with a demon, or Chuunin and above. Normal genin CANNOT learn summons.