Command and Conquer: Red Alert and its sequels are computer games by Westwood Studios, spun off from Command and Conquer. The series takes place in a sci-fi Cold War era where the Allied forces fight a large battle against the Soviet forces in a war for either destruction or domination of each other.
In Red Alert, the German scientist, Einstein, creates a Chronosphere, a device which he uses to go back in time and kill Adolf Hitler. This upsets the entire balance of world power, leading the Soviets to start a massive invasion of European countries. (The actual game involves the player fighting on one side of the resulting battles.)
Red Alert was praised for its user interface, which was much more developed then other games at the time. For example, there are no limitation to the amount of units one can select. One also can give a unit many orders at once, which it can execute in sequence.
In Command and Conquer: Red Alert 2, the Soviet leader, Alexander Romanov, invades America. The Allies are composed of Germany, France, America, Korea and Great Britain; the Allies fights a battle against the Communist Soviet forces. The Soviet forces, consisting of the armies of Russia, Libya, Iraq and Cuba, successfully take over most of America before they finally are defeated by the remaining Allies.
In Red Alert 2: Yuri's Revenge, after the war between the Allies and the Soviets, Romanov's Chief advisor, Yuri the psychic, breaks off from Russia and forms a renegade faction, much like CABAL in Tiberian Sun: Firestorm. Yuri's goal is to take over the world and use mind control to bend all its inhabitants to his will. This expansion game radically changed the course of the story, creating a new third force that even causes the Soviets and Americans to unite at times against the common foe.
Games in the series are: