- "Since a long time ago, Irregulars have brought change and chaos to the Tower. Also, they all possessed an enormous strength which became a symbol of fear within these walls."
An Unchosen Irregular (비선별인원, biseonbyeolinwon; "members who have not been chosen" or "Irregulars"), more commonly known as simply an Irregular, is someone who was not selected from within the Middle and Outer Towers to climb the Tower through Headon's normal selection of Regulars, but who entered the First Floor from the outside.
Nature and DefinitionEditIn the current political system, Headon visits the Outer Tower and the Middle Area to select Regulars. In this system, Irregulars are called "unchosen Irregulars" and Regulars are called "chosen Regulars" or "selected chosen". It is unknown if this current selection process is part of a contract Zahard made with a Guardian like Headon. It is assumed Headon's choice reflects the Tower's choice and in turn, the Tower's Rules.
Politically, Irregulars are viewed as beings who have entered the Tower and in turn, the Inner Tower, without being chosen by the Tower to enter. According to Yuri Zahard, they're "probably not too welcome" and she assumes Headon doesn't like Irregulars. And according to Ship Leesoo, Irregulars have "opened the door themselves of their own will" and their act goes "against the Tower's Laws". In addition, they violate the restrictions set by the Guardians when manipulating Shinsoo and this is likely considered further proof of their violation of the Tower's rules.
"Irregulars have all brought great change" and "chaos into the Tower" and "all the people in the center of the Tower" (assumed to be the Ruling Class and many of those serving the Zahard Empire tremble at them.)
Only Irregulars can receive challenges directly from the Guardians. Presumably, this means that before the creation of the Regular system, only those who would now be termed Irregulars were able to climb the Tower at all; it may also mean that only an Irregular can challenge Floors that lack an administrator.
The most important thing about an Irregular, at least to FUG, is that they, as beings from the outside, they are "free of all the contracts of the Tower"; most importantly to FUG, this means that they are capable of killing Zahard, who has a contract with the Guardians that guarantees that the inhabitants of the Tower can never kill him.
Most Irregulars have shown exceptional power from the moment they entered the Tower, but it is unknown whether this is a universal property of Irregulars, whether it's something they naturally have as a result of their origin or whether such power is usually just a prerequisite to forcing your way into the Tower in the first place.
Zahard and the Ten Family HeadsEdit
Officially, the term Irregular refers to those who have entered the Tower in defiance of the existing system; therefore, Zahard and his companions might not be considered Irregulars, despite entering from the outside. However, in Of the Tower's Weapons, Ashul Edwaru seems to group Zahard among their number, as does Yu Han Sung, indicating that they might be retroactively considered such despite (or perhaps because of) the Regular system not existing in their day.
Characteristics of IrregularsEdit
Irregulars possess enormous strengths which eventually become a symbol of fear.
They are extremely good at manipulating Shinsoo. For example: Eurasia Blossom proved this by "accelerating" the Shinsoo in an area, she could instantly kill 99% of the population living there. Another example: is the rumor that Enryu is able to create life with Shinsoo.
They also possess an extremely high Shinsoo resistance. This means high viscosity of Shinsoo doesn't restrict their movements.
According to Androssi Zahard, said she felt she shouldn't fight Rachel and had this feeling she came from "a different place from us". It seems the Princess was unsettled enough to join up with Rachel. She even accepted and obeyed Rachel's request, to not fight Baam's team. Something similar might also have attracted Koon Aguero Agnis to Baam, as Aguero was one who never trusted others and who never talked to others unless necessary. Yet Aguero thought that Baam was too special, to be ordinary and even went out of his way, to help him, risking his status.
If this "otherworldly presence" is indeed a trait of every Irregular, then it might explain why Zahard and the 10 Great Warriors were able to conquer the first 134 Floors to form the Zahard Empire. It might even explain the great influence of Urek Mazino and the Walhaiksong, why Baam was able to gain so many friends/allies in Season 1 and so on. It's also possible some are able to resist this "feeling" and instead, challenge the Irregular. Even in combat, Zahard couldn't take Mollic Won P. GR lightly and instead, the King reached a settlement where he became one of the 3 Lords. Now, Mollic Won P. GR is one who fights aggressively and his charisma is capable of overwhelming all 130+ Rulers during the Ruler's Conference.
Most Irregulars are known for notable acts like Phantaminum storming Zahard's Inner Palace, Enryu killing a Guardian, Urek Mazino fighting toe to toe with Arie Hon and then being deemed stronger by the latter. Also there are some, who are less famous.
Speculation and ControversiesEdit
The current testing system, in which Regulars are selected by Headon, was likely established by Zahard after he conquered the Tower up to the 134th Floor. Since only Irregulars can request to be tested directly by the Guardians, it follows that the only an Irregular (or those travelling with an Irregular) can actually reach the top of the Tower. This implies that the original purpose of the Tower may have been solely to test those now known as Irregulars.
For the longest time, there was an extensive debate in the fanbase over whether or not Rachel qualified as an Irregular, stemming from the unusual way Headon addressed her in Chapter 76 - the fact that he specifically said that she was "not chosen" (an unusual wording, since by the normal definition all Irregulars are unchosen) and debates over just what it means to "open the door" led many to believe that either Rachel or Baam was not an Irregular. SIU finally confirmed that both were Irregulars in a live chat with fans, but what, if anything, Headon meant when he said she was 'not chosen' (and, by extension, implied that Baam was) remains unknown.
- Zahard and the 10 Great Warriors; as noted above, listing them as Irregulars is controversial (likely even in-setting.)