They have large, deep chests and noses with wide nostrils, improving their ability to breathe the extremely thin Martian atmosphere. Their eyes are large and sensitive to very low amounts of light, and their ears have been enlarget to better capture sound.
The Martian upper classes also indulge in gene-tailoring for esthetics, so that many wealthy individuals are almost inhumanly beautiful.
Skilled in genetic engineering, they have already made the first strides along this dark and evil path by creating genetically altered slave races like the Workers and the Terrines, as well as buidling a mighty battle fleet that prowls space preying on weak and defenseless ships of the other planets.
Once a civilization of bold corporate pioneers and adventurers, the Martian society has degenerated into a rigid castehood of executives, managers, and workers. The executive culture of Coprates Chasm (the most extensively terraformed area of Mars) is glittering, decadent and martial. High-ranking men often dress in militaristic uniforms that double as business suits and sneer at the so-called "lesser planets." Upper-class Martian women are glittering social butterflies whirling through a round of gay parties that mask the savage intercorporate battles going on beneath the surface.
Every "civilized" Martian is tied to or affected in some way by RAM, a political/economic/military megalith descended from the mighty Russo-American Mercantile Corporation that was formed in the 21st Century. The Martian elite lives in massive pyramidal arcologies on the floor of Coprates Chasm, overlooking tranquil artifical lakes and forests. Their forms of entertainment are theater, film, parties, duels, and ice yachting.
Along the walls of the chasm live the managers, the middle-class functionaries of the Martian civilization. The manager cities are bleak, featureless malls with antiseptic plastic furnishings. Their main entertainment are watching the tri-dee, eating synthetic foods, and scrabbling for a few extra meals. There are no restaurants, movies or parks in the manager cities. Managers' lives are not uncomfortable - they live and work in clean apartments and offices - but they are also not fulfilling. Every manager works hard for the day when he too will be able to live in the glittering pyramids of the executives. Very few of them live to see that day.
Back in the deep tunnels behind the chasm walls live the Workers - unintelligent slaves who take care of the real grunt work of harvesting, planting, mining, and waste disposal. The Martians have crafted other types of gennies, mostly variants of the Worker that are designed for specific purposes. The most feared of all Martian gennies are the Terrines, elite soldiers manufactured by RAM. Also formidable in their own way are the Desert Runners who prowl the wide-open expanses of the planet.
Far out on the high, chilly Martian deserts are the various anarchists, lowlifes, and desert rats who refuse to toady and won't fit into the corporate system. They are tolerated by RAM only because they can do some of the dirty work that require more intelligence than Workers have. Whether tending the food farms of the shallow Boreal Sea, maintaining the obsolete and run-down spaceport on the ground at Pavonis, or monitoring the weather stations and surveillance outposts sprinkled throughout the wilderness, these independents eke out a meager existence far removed from their corporate relations.
Advantages: Slightly more nimble and more charismatic than normal humans, slightly less vulnerable to radiation poisoning, cold, and suffocation. Able to hear faint sounds that escape the notice of humans, which makes them more difficult to sneak up on. Able to make out images in dim light, which makes them better at hitting a target in combat under that condition. Aside from all the above, the biggest advantage of being a Martian is ... being a Martian.
A character who is backed by RAM could have access to great amounts of technology and manpower (specifically, gennie power) that would enable him to succeed where a non-Martian would fail.
Disadvantages: Generally weaker and more frail than humans because of their affinity for lower gravity, which also makes them more susceptible to damage from falls and other physical trauma. Vulnerable to the effects of extreme heat. Sensitive ears cause them to be hampered by loud noises, and sensitive eyes give them problems in bright light.
Last but far from least, the disadvantage of being a Martian is that most of the rest of the solar system identifies you with RAM and thus sees you as an adversary. It can be very hard for a Martian to make friends with non-Martians, but a Martian in a player character group that also includes members of other races might be looked upon more favorably.
Role-playing Notes: A Martian player character is not a RAM-type "bad guy." (Characters of that sort, such as the evil Simund Holzerhein, are NPCs whose actions are controlled by the referee.) There are plenty of Martians - even some highly placed in the organization - who don't agree with everything that RAM is doing, and it is from this group that a Martian PC will come. Of course, this means that you'll have to conceal your true feelings whenever you're on Mars or in the company of RAM loyalists - but that's part of what makes role-playing a Martian fun and challenging.
Ability Score Modifications: -1 Str +1 Dex -1 Con -1 Wis +1 Cha