Z/X (ゼクス, Zekusu), also known as Z/X Zillions of enemy X, is a collectible card game produced by Nippon Ichi Software and Broccoli. It is marketed as the first "free" collectible card game, with a free deck offered to players at card shops and events in Japan. A PlayStation 3 game titled Z/X Zillions of enemy X: Zekkai no Crusade, developed by Nippon Ichi Software and produced by Broccoli was released in Japan on May 23, 2013. A manga adaptation written by Broccoli with art by Karegashi Tsuchiya began serialization in Shueisha's V Jump from September 2012. A 12-episode anime television series adaptation titled Z/X Ignition aired between January 9, 2014 and March 27, 2014.

A new anime series was announced in February 2015, which was later revealed to be an adaptation of a new manga series titled Z/X Code reunion. It is written by Tatsuhiko Urahata with art by Takuya Fujima, and it began serialization in V Jump from September 2017. The anime adaptation is produced by Passione and aired between October 8, 2019 and December 24, 2019. The anime is licensed in North America by Sentai Filmworks.