An extremely powerful torpedo of high-energy plasma used by the Romulan, Klingon and Cardassian militaries. In its earliest known form, it released enveloping energy plasma upon detonation, forcing its target to implode. However, early plasma torpedoes encountered by Starfleet were plagued with limited FTL ranges, so much so that its destructiveness lessened to the point of inefficacy. Romulan plasma torpedoes at least were capable of multiple yields.