While it may not have been the first real-time strategy game ever, Dune II was definitely a granddaddy of the genre, and it's now free to play in your web browser.
Spawned from Frank Herbert's novel "Dune," cited as one of the most popular examples of sci-fi, Dune II helped pave the way for modern RTS games like Command & Conquer, StarCraft, early Warcraft games, and others.
First released on MS-DOS in 1992, most generally remember the version that hit Sega Genesis the following year. As other games used it heavily as a foundation, those who never played it will find the gameplay fairly familiar to Warcraft, StarCraft, etc.
Buildings can be constructed allowing for new vehicles, and troops, resources gathered (replace spice with tiberium), different factions, fog of war, all the staples of the modern RTS game are present and accounted for.
When the Amiga version of Dune II was released in 1993, it was met with positive reviews, receiving 85% from "CU Amiga" magazine, and Game of the Year by "Amiga User International." It was later ranked the 11th best game of all time by "Amiga Power" in '96, was entered into GameSpy's Hall of Fame, and was one of Time's 100 greatest video games of all time. Semi-remakes eventually made their way onto PlayStation 1 and Windows PC in 1998.
Even after the long years, the game still manages to hold up. If you want a taste of history, you can go play the game by clicking this link. Just watch out for those sandworms.
