Ice Warriors are the warlike inhabitants of Mars who have adapted to their planet's cold, arid environment. There are two distinct orders in the military hierarchy: the Ice Lords and the Ice Warriors themselves. Ice Lords are the officers, performing the role of diplomat or expedition leader; Ice Warriors are the NCOs and ordinary soldiers that are assigned bodyguard work on diplomatic missions.

The Ice Warriors have a long tradition of expansion by military conflict, and their solutions to problems are usually direct and violent. Yet they are capable of great subtlety, harnessing their scientific advances to adjust the climate of planets to render them suitable for occupation. Their technology, however, is heavily based on trisilicate, a mineral that is abundant on Mars and which they are eager to exploit sources of. Trisilicate is the material used in their electronic circuits, performing much the same role as silicon does in Earth technology.

Like humans, Ice Warriors are a political species and able to recognize that negotiation, not war, is sometimes the answer to conflict or the advancement of their civilization. At one time the Martian empire has been part of a federation of planets that has included Earth, Alpha Centauri, Arcturus and Peladon; at others, however, the Ice Warriors have been bent on the domination of Earth. It cannot be assumed that the Ice Warriors are automatically the enemy: they may well be allies!

It is easy to understand why Ice Warriors were mistaken for Vikings when they were first discovered on Earth, frozen in a glacier. Their armoured, scaly carapace, ridged limbs and helmet make them look as if they belong to an ancient civilization. Tufts of fur stick out from the joints in their green armour, however, and at 2 to 2.2 metres tall, they are clearly alien. Ice Lords are slightly built versions of the Ice Warriors, without the heavy carapace. Instead of hands, both types have heavy pincers.

Seemingly betraying a reptilian background, the Ice Warriors speak in low, sibilant tones; even when silent, their breathing sounds laboured. Ice Warriors tend to move slowly and deliberately.