The most dangerous class of missiles in the GCN ranking scheme. Doomsday Missiles have in common the ability to wipe out an entire civilization, either from the immediate denonation of the warhead, or from the effects of the aftermath. Examples of Doomsday class missiles include the Snowspringer Missile, the Captivity Missile, Velvet Ant Missile and the Apokalypse Missile. Since a civilization need not be spread out over a vast region to be considered valid, the GCN ranks any missile that can have a deadly affect on a region of over five miles in radius to be in this category.

Though some missiles can spread damage much further than this (for example, the Crust Crusher Missile can affect a seven mile radius), they are not included in this category because their effects are not strong enough to pose a mortal danger to life outside of their impact zone. The Crust Crusher, for example, causes massive shock waves, but these are not enough to completely destroy a civilized region of over 5 miles, as its true impact is only felt within a three mile radius.