Sin Piedad (2018) (Spanish for "No Mercy") was a major professional wrestling event produced by the Mexican Lucha Libre promotion Consejo Mundial de Lucha Libre (CMLL). The Sin Piedad show took place on January 1, 2018 in Arena México, Mexico City, Mexico. The 2018 Sin Piedad was the 14th event under the Sin Piedad name and the third year in a row CMLL has held the show on New Year's Day. The main event was a traditional Lucha de Apuestas, or "bet match", where long time rivals Sam Adonis and Negro Casas put their hair on the line. When Casas won the third and deciding fall Adonis was forced to have all his hair shaved off. The undercard featured five additional matches, four best two-out-of-three falls six-man "Lucha Libre rules" tag team match and one Best two-out-of-three falls tag team match Production Background The Mexican wrestling company Consejo Mundial de Lucha Libre (Spanish for "World Wrestling Council"; CMLL) has held a number of major shows over the years using the moniker Sin Piedad ("No Pity" or "No Mercy"). CMLL has intermittently held a show billed specifically as Sin Piedad since 2000, primarily using the name for their "end of the year" show in December, although once they held a Sin Piedad show in August as well. CMLL has on occasion used a different name for the end-of-year show but Sin Piedad is the most commonly used name. All Sin Piedad shows have been held in Arena México in Mexico City, Mexico which is CMLL's main venue, its "home". The 2018 Sin Piedad was the third first show to be held on New Year's Day after being held on the same day in 2016 and 2017. Starting in 2011 CMLL has been promoting a New Year's Day show with bigger, more prominent and promoted matches, although they did not specifically promote the shows under a special event name, they were simply a special version of their weekly Arena Mexico shows. Starting in 2011 CMLL added at least one high profile match to their shows, slowly building them into a special event. in 2011 the show featured the annual Reyes del Aire ("Kings of the Air") tournament, won by Ángel de Oro. In 2012 the January 1 show saw Hombre Bala Jr. and Super Halcón Jr. defeated the team known as Los Rayos Tapatío in a Luchas de Apuestas, masks vs masks