GURPS 4th edition. Mars Attacks

Earth Is Under Attack!

The Martians descended upon Earth without warning. Saucers filled the skies. Blaster-wielding soldiers, giant insects, and unstoppable robots slaughtered the human defenders on the ground. It could have been the end of humanity – if not for the brave scientists of the Novas Vira, the only ones who saw the invasion coming! Now the fate of Earth hangs in the balance as both sides turn to science, desperately inventing new weapons and defenses in the hope of finding the one that wins the war.

GURPS Mars Attacks contains everything you need to join the fight and make a difference:

Choose your side. Are you among the conquerors here to grant Earth the honor of being added to the Martian Empire? Or are you fighting to save your planet – either on your own or as part of the Novas Vira, Tiger Corps, or United Earth Alliance?
Set the scope. Play unprepared civilians stepping up to face Martian raiders, bold saucer pilots defending troops from waves of human jets, high-level officers making decisions that impact the entire war, or anyone else you can imagine!
Lock and load. It'll take spirit to win this war, sure, but also technology. Learn about the weapons, defenses, vehicles, and strange inventions of both sides – and take advantage of streamlined rules to make new ones.
GURPS Mars Attacks requires the GURPS Basic Set, Fourth Edition. The detailed setting and descriptions of Martian society and technology can be used with any game system.