Gravity-Activated Mode guided missile

". . . a Plex-fired GAM is the best seek-and-destroy weapon I've seen for use against repulsorcraft. It's fast, and almost impossible to shake once it locks onto a target. I admit the GAM's visual tracking system can be confused by other images in the sky. Good evasive maneuvers can lose the missile, too. But once it's caught a repulsor signature, that craft is gone."

―Imperial Trooper Reynol Kosk

The Gravity-Activated Mode guided missile ("GAM") was a guided missile developed by Merr-Sonn Munitions for use with their PLX-2M portable missile launcher. It possessed two tracking modes, selected at the push of a firing stud on the missile launcher: EPR mode, which locked onto high-level infrared sources such as vehicular or missile exhausts, and the namesake GAM mode, which first tracks a target's silhouette until close enough to home in on the gravity-wave anomalies resulting from an active repulsorlift. The silhouette-tracking system could be evaded by careful maneuvering or confused by other objects above the horizon, but it was extremely unlikely to lose its target once close enough to acquire a repulsor signature. The missile was capable of pursuing its target for forty kilometers before expending its fuel.

In addition to the PLX-2, GAM missiles could also be used by the PLX-4 Missile Launcher and the LX-80 anti-infantry missile emplacement. They cost 600 credits.

Sources

• Imperial Sourcebook (First mentioned)
• The Last Command Sourcebook
• The Thrawn Trilogy Sourcebook
• Rules of Engagement: The Rebel SpecForce Handbook
• Gundark's Fantastic Technology: Personal Gear
• Hideouts & Strongholds
•  portable missile launcher in the Databank (content now obsolete; backup link)
• Star Wars: Edge of the Empire Core Rulebook