The level of technology available when the vehicle is designed has a significant impact on what can be included in your vehicle. The Drawing Board considers nine levels of technology, referred to as TR (Tech Rating). TR 0 is the modern-day, 21st century world. Negative TRs indicate more primitive technology; positive TRs indicate higher, science fiction technology.

This is stone-age technology. Contrary to popular opinion, however, stone-age people did have technology, and they did have vehicles. Said vehicles were limited to rafts, dugout canoes, travois and sledges, but they did exist. Some advanced communities used rollers to help transport heavy objects on land.

The ancient world had surprisingly advanced vehicles, especially ships and chariots. While sails still employed very primitive rigging, oarsmen made up the gap, and animal-drawn land vehicles such as carts and wagons were quite common. The chariot emerged as one of the most dangerous mobile threats on the ancient battlefield.

The Middle Ages saw a massive leap forward in shipbuilding, including better sails and better hulls. Superior harnesses for animal power allowed for better wheeled vehicles, and runners on snow worked better than the older sledges. Improved steering on wagons and carriages made them easier to maneuver and more comfortable to ride.

Sails reached their pinnacle in design during this time period, but new, more powerful options began to appear. The introduction of steam power led to the development of paddle wheelers. While this new technology wasn't yet sufficiently compact or efficient for land vehicles, new advancements in metallurgy led to better suspension, making land travel easier and more comfortable. Most importantly, however, the development of firearms revolutionized vehicle-to-vehicle combat.

The rise of industrialism saw an explosion in vehicle technologies. Steam-powered railways, automobiles, tanks, the development of the airplane…all of this happened against a backdrop of major world conflicts. This is the earliest time-period in which submarines and airplanes become viable.

This is the modern era, the 21st century. Aircraft fly faster than the speed of sound; trains have been streamlined to operate at ridiculous speeds as well. Spacecraft are still in their infancy, but have become common enough that people no longer view them as science fiction impossibilities. Nuclear power allows ships to remain at sea for years, or allow submarines to remain submerged for weeks.