The Door Test is a test held on the Second Floor and was administered by Yu Han Sung. Each team (of three Regulars) is given three hidden and slightly metaphorical clues and then have 10 minutes to choose the "correct" door between twelve identical ones. In order to pass the test one must open any door within 5 minutes. The purpose of this test was to not determine whether the hint given was correct or not, but rather who would make a decision and take action.
It was noted by Koon that more than half of the tested Regulars failed the test.
When Baam, Koon and Rak came to the test, Koon took charge in order to find a way to pass. Koon, being a person who trusted no one, was annoyed when Rak decided to gamble and just open any door. But, to his shock and annoyance, the three passed the test.