Colonial Troopers (d20)
What if the first RPG was inspired by hard Science Fiction as written by Robert Heinlein¸ Poul Anderson¸ Isaac Asimov¸ and Frank Herbert instead of Tolkienesque fantasy?
Colonial Troopers is a science fiction RPG compatible with the original fantasy roleplaying game and subsequent editions¸ and other "OSR" games that follow in the mold of the original like¸ Guardians¸ Warriors of the Red Planet¸ and others. If your tastes run towards battle hardened combat armor¸ some attention to real physics¸ and explorations of just what it is to be human¸ you've found the right book. As in the fiction of the above writers¸ the players are confronted with an unforgiving universe full of wonders and deadly quirks of science ready to astound and enchant¸ and cull the unwary.