Kickers will only be allowed to take 60 seconds over a conversion, in line with the one-minute 'shot clock' that already exists for penalties.

Elsewhere crooked line-out throws will not be penalised if the opposition does not contest the ball and, like scrums, match officials will form up the set-piece within 30 seconds.

Scrum-halves will also be given more protection around scrums, rucks and mauls to ensure a supply of cleaner, quicker ball and faster phases of play.

The laws have been already been tested in a series of World Rugby events, including the summer's U20 World Championship and the Pacific Nations Cup.

A decision on 20-minute red cards - where an offending player can be replaced with another off the bench after 20 minutes - has been delayed until after the autumn.