The Mass Shadow Generator is a MacGuffin-like superweapon mentioned in the computer game Knights of the Old Republic II: The Sith Lords.

Created by Republic Lieutenant Bao-Dur during the last major events of the Mandalorian War, the MSG somehow uses the gravity of a planet to destroy everything within close range of the planet. How this is done is unknown, but many knowledgable characters comment on the ships being "crushed in the gravity" of the planet. It is possible, though not mentioned, that the weapon acts as a giant inertial compensator, thus increasing the sphere of gravity around the target, and increasing the gravity to crush anything in the gravity sphere.

In orbit around Malachor V, the Mandalorian armies were quickly destroying the battered Republic army sent to the planet. The general on site - Jedi Exile - activated the superweaon. The destructive power destroyed almost the entire Republic fleet, and destroyed the Mandalorian armies completely.

If the player has high enough influence with certain party members, it is revealed that Revan intended to destroy both fleets at once. The Republic fleet at M5 was filled with soldiers loyal to the Republic, and Revan intended to wipe out both threats to him, at the same time. Even the planet itself was extremely damaged.