1

Stone Age. The locals are unable even to work metals.

2

Bronze Age. They have metalworking and muscle-powered devices and tools.

3

Renaissance. Complex muscle, wind, and water-powered devices are possible, perhaps with crude firearms.

4

Victorian. Steam power, firearms, and industrial plants are possible for them.

5

Modern. They have equivalents of computers, synthetics, internal combustion, and other modern trappings.

6

Futuristic. Their technology encompasses many of the things we would consider plausible for hard sci-fi.

7

Alien. They have devices that work on logical but unknown principles and perform soft sci-fi miracles.

8

Enigmatic. Their tech is indistinguishable from outright magic, and it may actually be as much.