TECHNOLOGY LEVEL DISCUSSION: Technology Levels are one of the most popular and enduing tropes of Classic Traveller. They originated in the original Little Black Book (LBB) series and have been published and republished ever since across the many versions and editions of Traveller. In fact, they have been so popular that many other RPGs borrowed the concept and developed their own versions of it. In fact, ironically, other licensed and even unlicensed publishers of Traveller, not only used the trope, but developed their own versions of it! GURPS Traveller not only created its own TL system, but then decided to adapt Traveller to the GURPS TL system, rather than adapt GURPS to the Traveller system. This has led to much fan confusion since the system's level begin to diverge at the higher levels.
And there have been numerous fan interpretations of every type... comparing to superheroes, sci-fi novels, movies, and one of my favorites used a decimal system expanded further by a metric convention that featured a hundred levels.
Did the TL system originate with Traveller? Yes and no. Traveller certainly popularized the concept within RPGs, but similar concepts existed in previous sci-fi novels and other media publications. It's arguable.
What exactly is the definition of a TL or any one specific TL? Well, that's up to interpretation.
Even within Traveller's many editions and versions, there is considerable conflict. Many of the early levels were pegged to realworld dates... the 70's, 80's, 90's, etc. ...and that worked until Traveller's longetivity extended past a decade or so... And then, it began to break down. Computers, for instance, looked like they would be huge multi-ton affairs in the late 1970's when Traveller was first published, but as microelectronics began to develop in the 1980s and cone to maturity in the 1990's (...remember beepers? And brickish portable phones?), the old paradigms and futurological guesses began to fray. It was literally a trope in many gaming magazines of the day to make fun of of those trends. I loved those old cartoons.
And the names of each TL can be similarly ambiguous... How does one define "interstellar?" It seems easy on the surface, right? Between stars, right? Spaceships? Rocket? etc. ...but, when one digs deeper, its nebulously hard to define what interstellar is? Is an FTL drive required? What about sleeper ships and generation ships? Aren't they NAFAL, slower than light by convention? Defining a TL can be tough. Not so easy. In fact, quite a nut.
Like many fans, I made a number of stabs at defining technology levels and began documenting, comparing and contrasting, studying history, studying historiography, making notes and citations, and really made a go of trying to make sense of the TL system. What's on the wiki is the product of my multi-decade study and dabbling, as modified by a myriad of other fans, who have made comments and edits over the years. It helped that I was encouraged by Don McKinney, and later Marc Miller, among other Traveller personalities. Regardless, there is no way to design a system that will please all of the fans. One of the most common critcisms that I have received over the years is that TL:9-12 should be the boundary based upon the Imperial Encyclopedia, and not TL:10-12. It's valid criticism, but it also breaks the three-age system mentioned elsewhere in this long, rambling essay. The system also questioned what canon is and what it should be... Canon finally has some kind of official definition thanks to Don, but that system isn't so solid.
One of the first things I did was to try and break the system into commonalities, what's sometimes known academically as systemics or a periodicized chronology... Before the TL:1-33 span was set, I developed it into a thirty level system, but then it was officially pegged at TL:1-33 so I adapted it again ...to fit it to T5.
The current dabblings are modeled on what historians call the three-age system as in the stone age, bronze age, and iron ages. That was a useful tool. I also studied geological time, which was additionally useful. I read almost everything by other Traveller fans including the very talented Ken Pick who came up with all sorts of clever things.
The wiki's take on TL's and understanding them has hopefully kept the proper feel of Traveller, while omitting the sin of actually trying to put it to paper in detail, what famous Traveller fan Gypsy Comet might call: "...too much codification which inevitably leads to simulationist gatekeeping (...paraphrased)." Either way, I hope there's something in it that you might take away and enjoy, and... if not, chuck it all out the window and keep doing what you're doing. The #1 Rule of Traveller is to have a good time and enjoy yourself!
Enjoy! And technologize yourself!