TPK
A total party kill, almost always abbreviated to simply TPK, is roleplaying gamer slang for a event which results in the deaths of the entire adventuring party. TPKs are more common in some systems than others, due to the varying levels of lethality that abound in roleplaying games. In a typical 3rd or 4th edition Dungeons & Dragons game, for example, a TPK usually occurs because the players were too dumb or stubborn to back down from a powerful threat which they were meant to run away from, but in a game like Dark Heresy the threat of a TPK is ever present even in minor skirmishes.
Excessive TPK is usually the mark of a bad GM, who will view it as the gold standard of a "successful" campaign. Although a "rocks fall, everyone dies" scenario could technically be a TPK, they are not usually described as such.
Note the when the party in question is the total population of a planet, Imperial experts have created the term "exterminatus" to accurately describe the phenomenon.