Other trialled law changes announced by the WRU for their premier club competition will include any uncontested scrums having to involve eight players from each team, and if time expires and a mark, free kick or penalty is awarded, the referee will allow play to continue and a lineout allowed to take place if a team kicks to touch from a penalty.
WRU head of rugby Josh Lewsey said: "I am delighted the Welsh Rugby Union is taking a lead in the world game in regards to these law trials.
"Internally, we were already exploring innovative ways in which we could increase 'ball in play time', the focus on skill acquisition and match intensity.
"As such, these law trials are a superb fit for our intentions."
And WRU national match officials manager Nigel Whitehouse added: "We will be working alongside World Rugby, so this will be a detailed and focused process across the whole of the season ahead.
"As well as observing the games, we will be taking feedback from everyone involved to feed into our conclusion process.
"The results of the trial will then be fully assessed before any decisions are made about the long-term scoring system for the entire game."
-AAP