Practiced by Samurai, Seppuku was a form of ritualistic suicide that allowed the warrior to die honorably. Essentially he would disembowel himself and in an ideal situation there would be a close friend standing by ready to behead him as soon as his guts began to spill.
Burning at the stake, A historically popular method of capital punishment, if the victim were lucky he or she would be executed along with several others. This would ensure that the flame is much bigger and lead to death by carbon monoxide poisoning rather than actual burning.
Flaying, The act of removing a person’s skin from their body, this form of execution was often used in order to stir up fear, as the skin would typically be nailed in a public place for all to see.
Blood Eagle, Spoken of in Nordic sagas, the Blood Eagle involved cutting the ribs of the victim by the spine, breaking them so they resembled wings, and then pulling the victim’s lungs out through the opening. Salt would then be sprinkled on the wound
Walking the Plank, Mainly practiced by pirates and rogue seafarers the victims often didn’t even have time to drown before they were dealt with by the sharks that tended to follow the ships.
Bestiarii is a reference to those who would combat beasts in the days of Ancient Rome. Although sometimes the act was voluntary and performed for money or recognition, many times the bestearii were political prisoners sent into the arena naked and unable to defend themselves.