Test

Current Testing System
When a regular is climbing the Tower, he or she has to pass one or more tests on each floor.

The tests are created to determine whether the regular is worthy of going to the next floor. Generally the difficulty increases the higher one climbs. There are however a few exceptions, like the 2nd Floor and the 20th floor, where the difficulty is particularly high.

The tests are given to the regulars by either the Guardian of the floor or, more often, by the Guardian's proxy, the floor's Ruler. Each floor's Ruler had the right to decide the exam of his floor. But if the Guardian raises objections, the Ruler must follow the Guardian's wish. (Source: []) And these exams are then taken by future test takers, politically named as regulars.

History
When Zahard and the 10 Great Warriors entered the tower, they undertook grueling tests from the guardians and conquered the first 134 Floors of the Tower. However, some Floors were also conquered by Zahard's daughters. And as they climbed the Tower, they had helpers who were likely Tower inhabitants who took the Guardian's tests with them. (Source: [] Note that the "10 Great Families" part in Zahard's profile in there is contradicted by the information in here. [].)

Only Irregulars can request to be tested directly by the Guardian. And it seems they are allowed to take the test with Regulars or in ancient times, with Tower inhabitants(ones who didn't open the doors themselves).

It is quite likely Zahard gained control of ownership for each Floor from the Guardians as he was conquering the Tower. And then he started to place Rulers on each Floor he controlled. The current Testing system was likely only founded after Floor 134 was established as the Ruling headquarters of the Zahard Empire.

First Floor:

 * The Ball Test.

Second Floor:

 * The Deathmatch Test.
 * Lero-Ro's test.
 * The Door Test.
 * Crown Game (a bonus game).
 * The Position Test.
 * The Hide and Seek Test.
 * The Submerged Fish Hunt Test.

20th Floor:

 * Survival Round
 * World's Strongest Regular

43rd Floor:
No tests because Guardian is dead.