Technological index may vary from 0 to 18, more commonly ranging from 4 through about 10.  Higher numbers indicate greater capacity….The technological index is used in conjunction with the technological level table to determine the general quality and capability of local industry.  The tables indicate the general types or categories of goods in general use on the world.  In most cases, such goods are the best which may be produced locally, although better goods may be imported by local organizations or businesses when a specific need is felt.  In most case, the local citizenry will not be armed with weapons of a type which cannot be produced locally, although police or military units may be armed with weapons up to several levels above local technology.  Technological level also indicates the general ability of local technology to repair or maintain items which have failed or malfunctioned….The technological level tables have several spaces or holes, and such gaps should be filled in by the referee or the players when they discover items or devices of interest.

Tech. Index: 5. They have developed gunpowder (they have SMGs) but don’t know how to make chain armour; they have simple computers and radio, but no television, and despite the fact that there is quite a lot of water about they haven’t invented the submersible. They have fixed-wing aircraft but no nuclear fission. Altogether this is a pretty improbable world. Interesting to know, for instance, how those fixed-wing aircraft fly in what is virtually a vacuum, and what do the bureaucrats breathe?

Or Tom Wham’s more positive review in The Dragon #18:

Technology: 14 (very high) Non-industrial world…As you can see, “Grendal” nearly created herself.  The small population, high technology and government type seemed to dictate to me that Grendal is some sort of research base on a fairly inhospitable little world. And so she shall be when any adventurers land upon her.

So, technological level was seen as a suggestion to the referee about what could be expected from place to place.  The idea that technological levels might be shared from one star system to another, or that tech levels might get improved over time, were not easily grasped (though some referees did do both of these things). Even so, within those three paragraphs was a lot of implications to act as a guide for the aspiring referee:

• Tech levels range from 4 (roughly c. 1900 AD) to 10 (beginning interstellar flight).  That meant that a lot of planets were of not high enough tech level to produce their own starships.  This in turn meant that a few planets of high enough tech level (and population) probably would dominate interstellar relations.
• Local planetary conditions would shape how technology was used – Marc Miller would later refer to Fritz Leiber’s short story “A Pail of Air” to show how even a low tech level could be plausible on an (seemingly) airless world.  This particular aspect of “fleshing things out” was something generally observed in the breach by most referees in 1977.
• Higher tech level stuff might be available on a planet, but would likely cost more, due to importation and scarcity.  This in turn would provide a trade opportunity, for those ready to see it.
• Tech level would shape and limit the technology in use in interstellar relations.  If you had a really high tech item, you’d have to be prepared to either take it back to its planet of origin to get fixed, or be ready to make the repair yourself.