Threshold guardians keep unworthy people from going through doorways and gates. They can be against the hero, indifferent to the hero or even allies but they will still always serve their purpose. No one goes onto the next stage before proven to be worthy. They can be thought of as bouncers, bodyguards or doorkeepers and represent ordinary obstacles people encounter in life such as prejudice, bad luck and opposition.
Functions of the threshold guardian
This is the primary job of the threshold guardian. They provide resistance which helps shape the hero and act as stepping stones to test his strength and readiness before facing the big bad.
Signals of new power
They are early indicators of new power on the way. Heroes can also learn to see threshold guardians as useful tools to power up, like bodybuilders require heavy weights to build their muscles up. Threshold guardians are never defeated, but they can be incorporated into the hero’s way of life.
Source: Vogler, C. (2007) The Writer’s Journey (3rd edition)