Standard Tech levels
The OT Levels are those sections of the practices of Scientology which lead the person who is already Clear and has done the lower bridge with the Grades further up toward spiritual freedom and increased abilities. The abilities gained from doing these levels are assumed to be leading one towards the state of OT as above, but do not deliver the state of being able to operate without a body. A person who has completed one or more of these levels is often called "An OT", but that is something of a misnomer, and should not be confused with the state mentioned above. If there is a technology at this time on Planet Earth to achieve this state, it is not generally known.
The Church of Scientology currently delivers the levels New OT I, OT II, OT III, New OT IV, New OT V, New OT VI, New OT VII, New OT VIII. Although similar (not identical) services are delivered in the FZ, it is factually and legally incorrect to use the same names in the Freezone, tempting as it may be.
New OT I as delivered by the CofS is different from the OT I devised by LRH. The OT I in LRH's hand-writing delivered until about 1982 was a thirteen-step series of objective processes, done solo by the individual under the direction of the AO C/S. New OT I is based on standard problems processes, and addresses antagonistic people on a person's case. It's not really an OT level, being something that should have been addressed on OT Preparation auditing, but the long-running OT I had virtually been supplanted by the Sunshine Rundown, and that left a gap before OT II.
The levels of OT II through OT VII handle parts of the case which influence the person on various dynamics.
OT III is sometimes called "The Wall of Fire", a PR and marketing label rather than a descriptive one, although the level could often be considered hot or exciting, even dangerous. New OT IV is the "OT Drug Rundown". New OT V is "New Era Dianetics for OTs", or more commonly "NOTs". New OT VI is a course preparing the person to solo audit the next level, which is New OT VII, or "Solo NOTs".
Ron's Org levels
These level designations above VIII are peculiar to Ron's Orgs. They also do not lead to the quasi-theoretical state of "Operating Thetan". Some Freezoners consider these levels very valuable; some do not.
Captain Bill Robertson, who founded the Freezone, did his own research into solo auditing after OT III, as people would often audit thousands of hours on Solo NOTs, not always with good results. In 1985 he came out with the level Excalibur, originally called "Super-NOTs", which includes the equivalent of the NOTs level but is supposed to handle this part of the case for good. In Ron's Org it replaces the levels New OT V through New OT VII and is called "OT 8". The equivalent of the levels OT IV through OT VII in the Ron's Org are optional levels which the C/S lets the person only do if needed for him or her; they include the equivalent of the original OT IV through OT VII.
As Captain Bill continued to research the case that was left after the completion of Excalibur, he developed what are known as "OT levels 9-48", which are delivered by Ron's Org.
While all auditing and solo auditing up to "OT 8" addresses what could be called the "other-determined case" (things that have been done to the person by others), "OT 9-11" (called "The Phoenix"), "OT 12-13" (called "Super Power for OTs") and "OT 14-16" (called "The Grail") address the "self-determined" aspect of the case: Things the person has caused him- or herself and which remain incomplete cycles for him.
The upper "OT levels", the "Games Master" levels, the "Source Operation Levels" and the "VAST" levels (VAST= Valuable Application of Source Training) deal with pan-determined aspects of case. The person doesn't handle his own case, but deals with the dynamics and especially with Games.
There is more about Captain Bill's development of the Ron's Org "OT levels" in the article on Ron's Org.
It is highly recommended that someone wishing to gain spiritual advances on the OT levels or their equivalent first do his lower bridge under an experienced auditor and C/S; then do the proper training as a solo auditor. After Clear, and thorough training as a solo auditor, he should then do the levels in the correct sequence, studying the theory of each level using a checksheet and pack in a proper course setting, and solo auditing under a C/S trained in C/Sing those specific levels. The levels give a continuing gradient of improvement; the charges and subjects on a higher level usually cannot be viewed and handled properly when the lower levels are still charged and not adequately handled. The result of improperly run OT levels or equivalent, or levels run out of sequence, is usually an overwhelm of the person, with the subject and charges of the level being completely unreal or inaccessible to the person.
The Prometheus Reports Copyright-free solo auditing materials
Checksheets for Sections II and III Checksheets linked to The Prometheus Reports (but based on the original issues)