The Gate of Balance, also known as the Gold Gate and the Fifth Gate, is a gate that Magisterium students must pass through in order to graduate.
The gate only opens for those who have learned their lesson about having genuine intentions to do only good in the world, able to put aside their own desires and emotions for the good of others. Being able to pass through the gate will essentially mark the mage as one in good standing.
Passing through the gate will let images of the mage's memories, both good and him/her overcoming the bad ones, flash before his/her eyes.
Callum Hunt, Aaron Stewart, and Tamara Rajavi passed through the gate early during their Gold Year to clear Aaron's, now assuming Alex Strike's identity, name, a decision prompted by Master Rufus's suggestion. The three went through the gate, one after the other, and passed the test.