Most protagonists are depicted as imperfect; though heroic, they aren't flawless paragons of perfection, and will have some minor shortcomings to help the audience identify with them better. SuperBob can selflessly save the world on a daily basis, but mild-mannered Bob Trope will regularly leave the refrigerator door open. Key to the Heroic Vow is that it is a commitment the character keeps because he willingly wants to. There are no talismans or failsafes preventing the breaking of the Vow, nor are they needed -- the character's willpower and resolve are the only bonds needed.