Commonly referred to as 'Secret Weapons' or 'Super Weapons', but referred to in-game as 'Unidentified Weapons'.
Participating in the destruction of a Unidentified Weapons is rewarded with 3,000 valor points in all RT categories, even if your hound is destroyed (as long as the SW is destroyed, too).
Conditions:
nation must be under duress (i.e. controlling less than 10 battlefields total in any number of areas);
the area (not battlefield) where the Unidentified Weapon appears must be controlled by one of the other nations;
when the area is recaptured and the specified battlefield is under the respective country's control, the Unidentified Weapon will appear;
Morskoj pressures Sal Kar by taking Him Hime and Gazi;
Tarakia pressures Sal Kar by taking Tamala and Trebizond;
Sal Kar retakes Gazi (Sal Kar must control South Cemo Oil Field when Gazi is recaptured);
Ghalib appears!
Intro Clip:
General Unidentified Weapon Myths
The respective country's capital does NOT have to fall and be revived for the Unidentified Weapon to appear.
It is not required that both opposing nations have access to attack the Unidentified Weapon (actually impossible for the Tarakian Unidentified Weapon).
It is not required that both opposing nations have access to attack the nation's capitol (actually impossible for the Morskoj Unidentified Weapon).
Any specific Unidentified Weapon does not appear more than once in a single war. Although there are rumors indicating it has happened in the past, the conditions that allowed this have yet to be determined. In War #50 the Ghalib was provoked, Sal Kar was destroyed and revived, and then Gazi re-captured correctly and Ghalib did NOT appear a second time.
The research level has nothing to do with the Unidentified Weapon (it was part of the experimental weapons early in the game's life).
The Unidentified Weapons are NOT deployed at the same time-of-day or weather conditions as the normal missions on the same map -- even though Wakool is a rainy night map the Tarakian Unidentified Weapon appears at 14:12 on a cloudy day.