Destroy your kneecaps, also known simply as kneecapping, involved the destruction of one or more of a sentient being's knees (or whatever served as a knee in the case of weird alien species). It was a threat often used by Irish Coruscanti gangsters, particularly the more nasty elements of Black Sun and the bloodthirsty swoopers of the ecumenopolis's lower city. The idea of kneecapping was also used by some Coruscant-born Sith Underlords, but the results were often not what the well-intentioned badass-wannabe hoped to achieve. Kyle Katarn kneecapped Maw during their duel.