Tech Level Comparison Chart/meta

GURPS Traveller Notes

With the GURPS 3rd Edition book Steampunk, the concept of divergent technology was added.

• It should be mentioned that GURPS Lensman uses a totally different system called Tech Stages which due to the heavy use of superscience alternate technology and the way technology progresses in the setting don't easily convert to either GURPS or Traveler TLs.
• "The Imperium’s base TL is 10. (...) TL12 goods may be relatively common and cheap; TL12 technicians and operators are neither. " (GURPS 3e Traveler 2e pg 82) Note that this refers to the G3TL scale not the G4TL scale.
• "TL10 represents the “Imperial standard” technology, the best available to the Imperium throughout the era. The Terran Confederation progresses from TL9 to TL11 during the course of the Interstellar Wars." (GURPS Interstellar Wars pg 66)
• "However, at TL9 a number of superscience technologies appear and begin to advance. Interstellar Wars uses TL11+ to represent advanced levels of these superscience fields, layered over the stable TL:9-10 situation. (GURPS Interstellar Wars pg 159) This means that the TL system GURPS 4e traveler uses is inconstant with how super science is supposed to be handled.

David L Pulver, the author of GURPS 3e and 4e Ultra-Tech produced this chart on the GURPS forms for converting between GURPS 3e and 4e TLs:

upper half 3eTL7 = TL8
3eTL8 = 4eTL9
3eTL9 = 4eTL10 and some TL9-10^
3eTL10 = 4eTL11 and some TL10-11^
3eTL11 = 4eTL11 and some TL10-11^
3eTL12 = 4eTL11 and TL10-11^
3eTL13 = 4eTL11 and TL11^
3eTL14 = 4eTL12 and some TL11-12^
3eTL15 = 4eTL12^
3eTL16 = 4eTL12^

GURPS 4e TL concepts

TL(Historical+Divergent)

Example: TL(5+1) is a TL6, with historical Earth-like TL5, but somewhat different TL6 (same effects, different form). Characters not used to divergent technology suffer a -2 penalty. However, Steamtech points out that this is not always true. For example, "Sulfanilamide is classified as TL(5+1), but it was also a TL6 medication; no penalty should apply to the skills of Chemistry/TL6 or Physician/TL6 for working with it."

So in some cases divergent technology can be identical to "normal" technology. More over TL(x+y) can denote not only realistic alternative technology but superscience tech. So you can have the realistic drug Aspirin and supersciece drugs like Atavismine (a devolution drug; effectively what happens in Monster on the Campus (1956). Likely inspired by the Strange Case of Dr Jekyll and Mr Hyde novel.) coexisting in a TL(5+1) world.

The closest clear real world example of a divergent technology under GURPS 4e TL is Edison's 1896 Kinetophone (called a Speaking Mutoscope in SteamTech pg 52) at TL(5+1) when contrasted to Lauste's 1907 sound on film method at TL6. The first uses mechanical means so common to TL5 to sync picture and sound while the second uses electrical means that would be common in TL6.

Split technologies: TLPrimary (fields, TLSecondary). Example: TL8 (Communications TL7, Medical TL9). For societies more or less advanced in some fields.

Borrowed (familiar) technologies: TLKnown/Familiar. Example: TL1/2 (Bronze Age society familiar with Iron Age technology). For societies familiar with other level of technologies but not able (or willing) to replicate them.

Superscience

GURPS 4th Edition tried to fix the confusion and expand the TL scale with the addition of the superscience (^) category and the concepts of: borderline, split, and familiar technologies. It also eliminated the end date that TLs originally had allowing for a G4TL8 computer to be connected to a G4TL7 power grid that has a handful of still operational G4TL6 power plants.

Superscience involves technologies that violate our current understanding of physical laws (relativity, conservation of energy, etc.). For this reason any TL assigned to them is arbitrary. So FTL travel can be TL-6^, TL(6+4)^, TL-10^ or something else entirely depending on the setting. This is why broadcast power has two totally different TLs in G4: TL-6^ (Infinite Worlds, Gernsback) and TL-10^ (Ultra-Tech). For example, Azoth-7 is a G4TL(4+2) reality that has G4TL-4^ interstellar space travel which is normally an 11 on the GURPS 4e TL scale. Similarly many D&D worlds are G4TL-(3+3)^ - effectively TL-6 that thanks to magic diverged at TL-3; in the Spelljammer setting the "^" denotes manned interplanetary space flight which is normally an 9 on the GURPS 4e TL scale.

Since Jump drive is a form of FTL technology it gets a "^" and gives no indication on what the G4TL is, so while Jump drive tends to appear at G4TL9 that doesn't prevent an otherwise TL7 culture from developing Jump drive. For example, Homeline, a G4TL:8-9^ reality of GURPS Infinite Worlds has access to pocket and parallel universes which is Traveler TL-25 (TL-35). Then there is Engstrom, a G4TL-6^ reality that has created permanent access to eight other parallel universes (which are collectively known as the Nine Worlds).

Determining G4TLs

It should be noted not all GURPS 4e (or Powered by GURPS) books use the TL scale correctly so they are not always a good benchmark for where a technology is on the scale. For example, GURPS Prime Directive (a classic Star Trek setting ie TOS) highballed the TLs for G3 and continued using that scale for the G4 edition totally messing up the TLs as a result.

Using the GURPS 3e books themselves TOS was all over the TL:9-11 range for Weapons & Armor, a firm TL9 for Transportation (the transporter is a TL14 oddball), Antimatter was in the 10-12 range and Medicine was TL8. In GURPS 4e TOS is a mixture of TL6^ with some (6+3)^ and Power TL(6+4)^ thrown in.

EU Star Wars is G4TL8^ and nearly all pre 1940s science fiction is G4TL-6^ with the occasional higher TL appearing.

Using science fiction novels as TL inspiration has its own pitfalls. Even "hard" science fiction stories may be hampered by assumption of the time that turned out to be wrong. For example, Weinbaum's 1930s "Planetary series" is G4TL(6+3)^ as it was based on then current theories of the solar system which have since been shown to be wrong (hence the "^").

Further Notes:

• Rows of Technologies that are a mixture of "real" science and superscience will have the lowest G4TL for the nonsuperscience items combined with "^".
• When technologies don't exactly match the stated GURPS TLs and the two GURPS TL are effectively identical a GTLx note will be provided.