Tech Levels are a crucial part of GURPS system, and of the Infinite Worlds setting. Very simply, they can be listed on a scale from Tech Level 0 (Stone Age) through Tech Level 8 (Digital Age) to Tech Level As High as the Game Master wishes (sci-fi) which represents a general rating of a society’s highest achievement in technology. This is however complicated somewhat by a special nomenclature for split technologies (if a world is more advanced in some fields), and different technologies (psi, magic, science). This page will attempt to provide a brief overview. For full overview, see references.


Basic Set: Campaigns page 513 discusses having multiple versions of a skill for different tech levels and how you can save points by defaulting, using the modifiers from Basic Set: Characters page 168 which has 2 categories:



  • High TL (called High Technology in Classic)
  • Gadgeteering (allows access to cinematic New Inventions guidelines)


  • Low TL (called Primitive in Classic)

What makes a Tech Level?

'“Tech level” (TL) is a general rating of a society’s highest achievement in technology (or a certain type of technology).'(sic)

Please note that tech levels have somewhat changed between editions. The below chart is intended to represented the newest, 4th Edition. The biggest changes from Classic was the elimination of ending dates and the introduction of superscience. For the Classic version see Technology Levels (Classic).

Also note that GURPS Lensman uses a totally different Tech level system called Tech Stages.

General Tech Level Overview

TL Era Approximate
start date
Typical Monthly Pay[1] Monthly/ Standard Signature technologies
0 Stone Age Prehistory and later $250 $625 0.40 Counting; oral tradition.
1 Bronze Age 3500 BCE+ $500 $650 ~0.769 (100/130) Arithmetic; writing.
2 Iron Age 1200 BCE+ $750 $675 0.900 Geometry; scrolls.
3 Medieval 600 CE+ $1,000 $700 0.7000 Algebra; books.
4 Age of Sail 1450+ $2,000 $800 2.500 Calculus; movable type.
5 Industrial Revolution 1730+ $5,000 $1,100 0.4000 Mechanical calculators; telegraph.
6 Mechanized Age 1880+ $10,000 $1,600 0.16000 Electrical calculators; telephone and radio;
7 Nuclear Age 1940+ $15,000 $2,100 0.14000 Mainframe computers; television.
8 Digital Age 1980+ $20,000 $2,600 0.13000 Personal computers; global networks.
9 Microtech Age 2025+ $30.000 $3,600 0.12000 Artificial intelligence; real-time virtuality.
10 Robotic Age 2070+ $50,000 $5,600 0.11200 Nanotechnology or other advances start to blur distinctions between technologies...
11 Age of Exotic Matter $75,000 $8,100 0.10800
12 Whatever the GM likes! $100,000 $10,600 0.10600

Tech Level by Field

TL Transportation Weapons and Armor Power Biotechnology/Medicine
0 Skis; dogsleds; dugout canoes. Wooden and stone weapons; primitive shields; hides for armor. Human muscle power; dogs. First aid; herbal remedies; primitive agriculture.
1 Bare horseback; the wheel (and chariots); ship-building; sails. Bronze weapons and armor. Donkeys; oxen; ponies. Surgery; animal husbandry; fermentation.
2 Saddle; roads; triremes. Iron weapons; iron armor (including mail); siege engines. Horses; water wheels. Bleeding the sick; chemical remedies.
3 Stirrups; oceangoing sailing ships (longships, roundships, etc.). Steel weapons; early firearms; plate armor; castles. Heavy horses and horse-collars; windmills. Crude prosthetics; anatomical science.
4 Stagecoach; three-masted sailing ships; precise navigation. Muskets and pikes; horse artillery; naval broadsides. Improved windmills; belt drives; clockwork. Optical microscope makes cells visible.
5 Steam locomotives; steamboats; early submersibles; balloons and early airships. Early repeating small arms; rifled cannon; ironclads. Steam engines; direct current; batteries. Germ theory of disease; safe anesthetics; vaccines.
6 Automobiles; continental railways; ocean liners; submarines; aircraft. Smokeless powder; automatic weapons; tanks; combat aircraft. Steam turbines; internal combustion; alternating current; hydroelectricity. Antibiotics; blood typing and safe transfusions; heredity; biochemistry.
7 Nuclear submarines; jet aircraft; helicopters; manned space flight. Ballistic body armor; guided munitions; combat jets; nuclear weapons. Gas turbines; fission; solar power. Discovery of DNA; organ transplants; pacemakers.
8 Satellite navigation; SSTO ("single stage to orbit") spacecraft. Smartguns; blinding lasers; unmanned combat vehicles. Fuel cells; advanced batteries. Genetically modified organisms; gene therapy; cloning.
9 Robot cars; space elevators; manned interplanetary space flight. Electrolasers; heavy laser weapons; battlesuits; combat robots; designer viruses. Micro fuel cells; deuterium-hydrogen fusion; high-temperature superconductors. Human genetic engineering; tissue engineering; artificial wombs; cybernetic implants
10 Fast interplanetary space flight. Compact laser and heavy particle-beam weapons; Gauss guns; nanotech armor; nanoviruses; antimatter bombs. Aneutronic fusion; antimatter. Brain transplants; uploading; bioroids; uplifted animals.
11 Manned interstellar space flight. Compact particle-beam weapons; disassemblers ("gray goo"); defensive nanites. Portable fusion power. Living machines; cellular regeneration.
12 Faster interstellar space flight. Gamma-ray lasers; "living metal" armor; black-hole bombs. Portable antimatter power. Full metamorphosis; regeneration.
^ Reactionless thrust; contragravity; faster-than-light (FTL) travel; matter transmission; parachronic technology; time machines. Monomolecular blades; force-field technology; gravitic weapons; nuclear dampers; disintegrators. Broadcast power; cold fusion; zero-point energy; total conversion; cosmic power. Fast-growth clone tanks; psi drugs; regeneration ray.

"Note that TLs have start dates but not end dates. The innovations of a given TL fade as those of higher TLs displace them, but they rarely vanish completely. A blacksmith in 1850s England uses TL3 techniques to shoe the horses that pull the carriage the gentleman rides to catch his TL5 train to London – and those techniques might still exist in TL8, albeit as a quaint hobby." [2]

"Define a society’s TL by the tools and techniques in common use there – not by the calendar date. Different technologies don’t always advance in step. Some societies achieve a TL’s overall capabilities without all of its characteristic technologies – and sometimes without its signature technology!" [3]

TL Progression Start Dates

It can be argued that the Ultra-Tech chart[4] was little too conservative as in 2020 we are seeing some TL9 prototypes and it is not like we are on the accelerated track.

TL Accelerated Fast Medium Slow Retarded
9 2020 2025 2030 2040 2050
10 2050 2075 2120 2200 2500
11 2100 2200 2500 3000 7000
12 2200 2600 4000 8000 20000

Fine Tuning TLs

Because TLs have no end dates it is very easy for a culture to have a wide range of TLs even within a category. For example, there are still plenty of totally functional TL6 cars on the road even as prototypes of TL9 self driving cars are being built. In fact, it could even be argued that cars didn't really reach TL7 until the mid to late 1970s. There are built-in systems to assist in these and other complications, if the GM wants to have a more "realistic" setting.

Borderline technology

  • TLOld-TLNew. Example: TL5-6. For societies in transition from one tech level to another.

Split Technology

  • TLPrimary (fields, TLSecondary). Example: TL8 (Communications TL7, Medical TL9). "Realistic societies rarely have the same TL in every field of endeavor; they tend to be advanced in some fields, backward in others."[2]

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.

Divergent Technology

  • TL(Historical+Divergent). Example: TL(5+1) is a TL6, with historical Earth-like TL5, but somewhat different TL6 (same effects, different form). For alternate worlds which "look" different. Characters not used to truely divergent technology suffer a -2 penalty.

Equivalent TL

  • What the TL appears to be due to Magic or Superscience. It may or may not actually be that TL.[5]

Outside the normal TL scale (superscience)^

  • These are 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 TL1^[6], TL5^[7], TL6^, TL(6+4)^, TL10^ or something else entirely depending on the setting. This is why broadcast power has two totally different TLs: TL6^ (Infinite Worlds, Gernsback) and TL10^ (Ultra-Tech).

Tech Level Modifiers

This table is for characters using technology more / less advanced with regards to IQ based TL skills. In settings with superscience or magic this refers to the mundane TL not the Equivalent TL.

Equipment’s TL Skill Penalty
Skill’s TL+4 or more Impossible!
Skill’s TL+3 -15
Skill’s TL+2 -10
Skill’s TL+1 -5
Skill’s TL 0
Skill’s TL-1 -1
Skill’s TL-2 -3
Per extra -1 to TL -2

"Technological skills based on attributes other than IQ let you use technology; they do not assume any real understanding of the science or engineering behind the tools."[8] For these type of skills apply a flat penalty of -1 per TL of difference between the skill and the equipment. So a TL6 soldier could fire a TL7 gun at -1 skill rather then -5.

Non IQ Tech skills are Beam Weapons†, Boating†, Driving†, Environment Suits†, Gunner†, Guns†, Liquid Projector†, Parachuting, Piloting†, Sewing, and Submarine†.

Familiarity is in regards to a skill limited to a certain type of equipment. Skills with a specialization (marked with a † in the List of Skills) can have their own familiarity penalties with the default at -2.

Important note: Familiarity and difference in TL penalties are generally cumulative. For example, you have Armoury (Small Arms; beam weapons)/TL9 and try to repair a TL10 portable railgun. The skill states that this unfamiliarity incurs a -2 and so you are at -7 to skill. (-2 for being unfamiliar with the weapon and an additional -5 for the rifle being 1 TL above you).

Similarity, you have Beam Weapons (pistol)/TL9 and try to use a TL10 laser rifle. The skill states that the specializations default to each other at -4 and so you are at -5 to skill. (-4 for being unfamiliar with the weapon and an additional -1 for the rifle being 1 TL above you)

The exception to this is in regards to DX-based mature technology that remains stable over long periods of time (such as a canoe) when just the familiarity penalty applies. "This exemption doesn’t extend to other skills, or even to IQ-based rolls for DX-based skills."[9]

Improving the TL

Characters have two realistic options (Building Up Local Technology and New Inventions) and one cinematic option (Gadgeteering) for improving the local TL. Generally these methods are expensive in terms of money and time.

"The equipment listed for a TL does not appear all at once as soon as a society enters that TL. Instead, items appear gradually after that date."[2] This is as true within a category as it is between categories.

Real World Examples

These real world examples are provided in GURPS Low-Tech p. 12. There are no superscience examples for obvious reasons.

  • Polynesian Navigators: TL0 (Seafaring TL2)
  • The Walls of Jericho: TL0 (Construction and fortification TL1)
  • Mayans: TL(0+1) (Mathematics TL3)
  • African Metallurgy: TL1 (Metallurgy TL2)
  • Medieval Medicine: TL3 (Medicine TL1-2)
  • China (c. 1250): TL4

Figuring out Classic TLs in 4e

See Divergent Technology, Equivalent TL, and GURPS Adaptations (Assigning Tech Level note) for more details.

The change in the TL scale between GURPS Classic and GURPS 4e resulted in many future TLs being classified as Alternate technology and many divergent technologies (such in Steampunk) being folded into the standard TL scale or becoming superscience. As a result many of the future TLs in GURPS Classic books don't quite line up with 4e TLs causing problems. David L. Pulver provided very rough conversion chart in the GURPS forums.

It should be mentioned that dates in either TL system are approximations:

Television, which GURPS states is a TL7 device, goes back to 1909 which is firmly in the realm of TL6. Furthermore the first commercial TVs similar to what we would recognize appeared in the 1930s and were used to show the 1936 Summer Olympics and the coronation of George VI in 1937.

Similarly, personal computers (TL8) appeared before 1980+: Xerox PARC's Alto (1972), MITS Altair 8800 (1975), and the Apple II (1977) are some of the better remembered ones today.

Heck, we have fledgling artificial intelligence and robot cars (TL9) right now...well before the 2025+? date given by GURPS. Also GURPS puts fuel cells at TL8 even though the first reference of them occurs in 1838...well in TL6. The Gemini and later Apollo spacecraft used fuel cells and that is firmly in TL7.

GURPS 4e puts alternating current as TL6 (1880+) but first alternating current generator was invented in 1832 and the first public use of AC systems were in the late 1870's...well before the "start" date for TL6.

Pyramid Themes

Pyramid groups TLs into three 'themes' which it alternates between with each issue[1]. These themes are a useful way of roughly describing the time period and correspond to the various GUPRS tech books:
These are 'rough' because for example Modern goes from the 1700s through to early 2000s, so Modern includes everything from cowboys in the wild wild west to Neil Armstrong and the first moon landing.


  1. Basic Set p 517
  2. 2.0 2.1 2.2 Basic Set p. 511
  3. GURPS Low-Tech p 7
  4. GURPS Ultra-Tech p. 8
  5. GURPS Fantasy 66
  6. Harry Turtledove's "Herbig-Haro" which is a sequel to "The Road Not Taken"
  7. The Roxolan in Harry Turtledove's "The Road Not Taken"
  8. Basic Set 168
  9. GURPS Low-Tech p. 16
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