The Asia Rugby Championship in 2018 formed part of the World Cup qualifying process and, as such, did not include Japan who had already qualified as the 2019 Rugby World Cup host.

Hong Kong and South Korea were joined by Malaysia, promoted from Division 1, to compete in the 2018 series.

The format of the tri-nations series is a double round-robin where the three teams play each other twice on a home and away basis.

The team finishing on top of the standings at the end of the series is declared the winner.

The teams involved, with their world rankings prior to the 2018 tournament in brackets:[1] Source: asiarugby.com[2]