Technology Levels

One-pager. A Tech Level (TL) is shorthand for "how advanced is this?" — used to price gear, gate availability, and set the feel of a setting. It is a single number only because, on Earth, the threads of technology happened to advance together. They needn't anywhere else.

Tech is many threads, not one number

Technology isn't a single ladder. Read the table by column: each column is a thread that has its own level. For human history the threads stayed close enough together that one number is a fair summary — so a single TL is just that summary.

The Social/Legal column is not flavor: it's the substrate the others grow on. Without the joint-stock company, currency, and global trade you don't get integrated circuits or modular reactors — there's no capital, no supply chain, no fab, however sound the Physics. So the upper threads rest on Social/Legal, with one important asymmetry:

A culture can possess artifacts from above its Social/Legal level — looted, bought, or handed down by a patron — but it can't originate them. Warlords with assault rifles, yes; warlords manufacturing assault rifles, no.

For alien or fantasy civilizations, don't assume lockstep. A culture might have TL2 Physics and TL5 Biology because healing is magical; an alien race might reach the stars with no gunpowder weapons; a steampunk world runs TL4 Physics under TL6 Math. When threads diverge, give the threads that matter their own levels and ignore the summary number — but remember the Social/Legal floor: a thread can't be home-grown much higher than the institutions that would pay for and organize it.

The original 1985 scale badly underestimated information technology. Rather than pretend otherwise, this edition simply recalibrates: TL6 is defined by the computing and networks we actually got, so the threads sit back in rough lockstep for present-day Earth. The lesson survives as history — if we misjudged our own near future this much, don't assume an alien or fantasy civilization's threads line up at all.

The table

TL Era (≈) Math Physics Biology Social/Legal
0 Stone Age Tally, counting Fire, lever, knapped stone Foraging, herb-lore Band, kinship, custom
1 Antiquity Arithmetic, geometry Bronze & iron, wheel, sail Agriculture, domestication City-states, empires, written law
2 Medieval Zero, algebra, Arabic numerals Watermill, blast furnace, clockwork Crop rotation, hospitals Feudalism, guilds, canon law
3 ~1500 Symbolic algebra, logarithms Gunpowder arms, printing, ocean nav. Anatomy, early botany Nation-states, banking, charters
4 ~1900 Calculus, statistics Steam, electricity, telegraph, mass production Germ theory, anaesthesia, vaccines Representative govt, civil codes, labor law
5 ~1980 Computability, information theory Flight, fission, electronics, spaceflight Antibiotics, DNA, transplants Welfare state, human rights, world bodies
6 now Cryptography, machine learning Microprocessors, networks, electrification, precision weapons Genomics, gene editing, mRNA Global networks, data & privacy law
7+ Postulated Define per setting

Finer grain (quarter levels)

Whole numbers are usually enough, but quarter-levels are available when a setting needs to distinguish near-contemporaries:

Quarter-levels can apply to a single thread — "TL6, but Physics 6.25" — without dragging the others along.

Using TL at the table

Designer's Note: the original anchors stand — TL5 was about 1980, TL4 about 1900, TL3 about 1500 — but the present needed finer grain, and the future needs humility. TL6 has been recalibrated to match the information tech we actually got. I'm not presupposing FTL, fusion is a maybe, and I was badly wrong about computers once already. Threads, not ladders.