The RugbyWA Cup is awarded to the Fortescue Premier Grade Team that successfully defends or captures the cup throughout the home-and-away season. The competition begins with one team holding the cup, and with each match, the cup is on the line. If the holding team loses, the cup passes to their opponent. The team in possession of the cup at the end is crowned the RugbyWA Cup champion.

• Cup Holder: At the beginning of the season, the current holder of the RugbyWA Cup will be the team that won it in the previous year. If no holder exists, the cup will be contested in the first match of the season. 
• Cup Challenges: A challenge match initially occurs when the Cup holder is playing at home. The challenger will be the opposition team in these respective matches at the Cup holder’s home venue. Once a team has successfully defended the Cup two (2) times at home, all of the holder's subsequent matches in the competition are considered mandatory defenses, whether home or away. If the Cup holder has not defended the cup at least twice (2) at home, they cannot lose the cup playing an away game until so - once they have defended it twice, the Cup is on the line.
• End-of-Season Champion: The team in possession of the RugbyWA Cup at the end of the home-and-away season will be declared the champion and awarded the RugbyWA Cup for that year. 
• Uncontested Matches: If a match is forfeited, the cup will remain with the current holder unless the forfeiture is by the holder, in which case it passes to the opposing team.