A countdown timer on scrums and kicks at goal will be introduced in January to help speed up the game, says World Rugby.
The ‘shot clock’ means players will have 90 seconds to take a conversion and a minute for penalties, or the kick will be disallowed.
New rules also state scrums have to be started within 30 seconds and line-outs formed without delay, with penalty kicks to be given for timewasting.
The rules come into place on 1 January.
A clock for kicks at goal is already in operation in France’s Top 14.
BBC rugby union correspondent Chris Jones first reported the proposals in November, when the sport’s key stakeholders met.
World Rugby’s director of rugby, Phil Davies, said: “World Rugby, member unions and competitions will work with broadcasters and match hosts to implement on-screen [stadia and broadcast] shot clocks for penalties and conversions to ensure referees, players and fans can view the countdown, mirroring what happens in the LNR [French national league] and sevens.”
World Rugby hopes the changes will improve the flow of the game and reduce the reliance on Television Match Official reviews, which adds to stoppages in the action.
Water carriers will also only be permitted to enter the field of play when a try is scored.
“Only in a game with no tries, should a natural stoppage be used,” added Davies.