The First Wave
Warcraft: Orcs & Humans
After the release of Dune II, no new real-time strategy games were released for the better part of two years. As Blizzard's Bill Roper told Computer Games Magazine, "We couldn't believe that no one else, including Westwood, had ever done a game that had this real-time strategy element." So Blizzard itself decided to do it. In late 1994, the developer released Warcraft, which took the real-time strategy game out of science fiction and into the realm of fantasy. The stage was set for the next round of RTS battles: Westwood's modern weapons against Blizzard's magic.
By eschewing the futuristic vehicles of Dune II and changing the setting completely, Warcraft opts for a more personal combat motif: hand-to-hand fighting. This is something that had not been seen previously in a real-time strategy game. The most powerful units are still ranged attackers, though. Effective play in the single-player campaign usually consists of building enough hand-to-hand units to defend the ranged attackers, who can stand off and inflict serious damage. There are two resources to be harvested--wood and gold--and most builds require a combination of the two. The simple "harvest, build, conquer" model is still the same, but the genre has been slowly evolving.
The units on both sides are very similar: For example, they fall into identical categories (worker, foot soldier, mounted soldier, magic user, and so on), and the structures used to produce them have different names and artwork but have similar build dependencies. This was a formula that Blizzard would adhere to until it spectacularly broke this mold with Starcraft. But for the next several years, it was Westwood that implemented a noticeably different composition to the two sides in its games, whereas Blizzard did not.
The AI in Warcraft leaves a lot to be desired. It blindly attacks whatever it can find, and thus it's easy to distract and lead astray with decoy units. Furthermore, unit pathfinding is just as bad. Once an experienced player understands how the AI works, beating the game in single-player mode is quite easy. However, Warcraft does provide multiplayer capability, even if it's just via serial connection or direct modem link. Warcraft thus became the first multiplayer RTS game for the computer. There is also a random map generator, which was also a first for real-time strategy. As such, the groundwork for what would become a major element of RTS gaming, multiplayer skirmish play, was laid very early on in the genre's history.
Warcraft wasn't a blockbuster hit, but it did sell well, and indeed, it did well enough to convince Blizzard's then-owners, Davidson & Associates, to authorize the development of a sequel, which would end up being one of the biggest successes the RTS genre has ever seen. However, Command & Conquer came first.