Tissue Compression Eliminator

The Tissue Compression Eliminator, also known as the TCE, was a trademark weapon of the Master, especially so following his assumption of the appearance of the Trakenite Tremas. (DW: The Keeper of Traken)

As its name suggests, the TCE killed by drastically compressing the bodies of its targets to the point where life functions ceased. The Master liked to leave the shrunken doll-like corpses of his victims as a calling-card for the Doctor to discover.

The Master later attempted to improve the design of his weapon, but a laboratory accident resulted in both him and the aforementioned laboratory being reduced in size instead. This process did not appear to physically harm him. (DW: Planet of Fire)

The upgrade to the TCE later seemed to be perfected as on subsequent appearances targets appeared to be utterly disintegrated rather than simply killed and reduced in size.

The only known entity to survive a direct hit from the TCE unharmed was the Valeyard. Multiple shots from the weapon appeared to glance off him. The Master's attack on him took place in the Matrix and it is unknown whether the Valeyard's immunity was due to the unusual properties of the environment (which he had a considerable degree of control over) or his own unique status as a projection of a possible alternate timeline.

The TCE, despite its name, was equally capable of shrinking inorganic tissue: victims' clothes were also shrunk, and on one occasion the Master demonstrated the weapon by shrinking unoccupied space-suits. The Doctor once described the method by which the Master killed as Matter Compression, which seems slightly more accurate. However, one must always bear in mind that the Master is an insane evil genius and one must not expect everything he says and does to conform to the highest standards of rationality.

List of people killed by the TCE

 * Goodge (DW: Terror of the Autons)
 * Runcible's assistant (DW: The Deadly Assassin)
 * Unidentified Earth police constable (DW: Logopolis)
 * Aunt Vanessa (DW: Logopolis)
 * Various Logopolitans (DW: Logopolis)
 * Various Xeraphin (DW: Time-Flight)
 * Kamelion (used by the Doctor in this instance) (DW: Planet of Fire)
 * Unidentified Earth miner (DW: Mark of the Rani)
 * Unidentified Earth miner's dog (DW: Mark of the Rani)

Other uses

 * The Doctor was able to use the TCE to sabotage the Master's TARDIS. (DW: The King's Demons)
 * The Master shrank himself with it accidentally. (DW: Planet of Fire)
 * Used against the Valeyard in the Matrix, without effect. (DW: The Ultimate Foe)

Expanded Universe

 * During his first encounter with the giant mechanoid bounty hunter Death's Head, the Doctor was forced to use a TCE (which he just happened to have about his person) to defend himself against the mercenary. Death's Head was not injured but did find himself reduced to about the size of a normal humanoid, which he remained for the rest of his career. (DWM:Crossroads of Time)