Cook Islands won the biennial event two years ago but will not defend their title, choosing to focus their limited resources on November's Olympic Sevens Qualifier.
Newcomers American Samoa open proceedings against Solomon Islands at Sir Hubert Murray Stadium, followed by hosts Papua New Guinea against Tahiti, in the first round of matches.
The General Manager of Rugby PNG, Frank Genia, says pride and silverware aren't the only things on up for grabs.
"Although you could call this a dead rubber tournament, so to speak, it is crucial for the development of a lot of the Melanesian countries. For PNG in particular, we are using it as an opportunity to start to build and develop and establish our player pathways and develop our talent coming through, leading into World Cup qualifiers in two years. There's a lot of incentive here - there's a long road ahead - but it starts off this weekend".
The four countries will play each other once over the next nine days, with the top team declared the winner.