World Rugby is considering a global trial of a 20-minute red card as part of a raft of radical plans to broaden the appeal of the sport.

The proposal, where the player sent off is replaced by a substitute after 20 minutes has elapsed, will potentially go before the governing body's council in Dublin in May. 

Introducing a shot clock for scrums and lineouts, outlawing the "crocodile roll'' clear-out at rucks and lowering the tackle height in the elite game to the base of the sternum are among other possible rule changes.

More immediately, referees have been told to call "use it" earlier at breakdowns in a bid to speed up play and eradicate the use of "caterpillar rucks'', and also to crack down on water-carriers entering the pitch. 

The recommendations follow World Rugby's "shape of the game'' forum held last month in an effort to enhance rugby's entertainment factor. 

Twenty-minute red cards would ensure the offending player and their team are punished without spoiling the spectacle, particularly after an early dismissal.

The rule has proved popular in the southern hemisphere, where it has been trialled in Super Rugby Pacific. 

In addition to potentially expanding the use of a shot clock, which is currently used for penalties and conversions, unions and competition owners will be encouraged to stage further closed-law trials. 

These include the ball being played after the maul has been stopped once, not twice, further protection of scrum-halves at the base of rucks and scrums, and play on if a lineout is not straight but the throw is uncontested.

The article is not finished. Click on the next page to continue.