THE Rainbow Cup is to try out three law variations when it gets under way next weekend - red-card replacements, a ‘Captain’s Challenge’, and goal-line drop-outs.

The red-card system, which is already being used in Australia and New Zealand, will see sides being able to bring on a player 20 minutes after one of their team has been sent off. Either unused substitutes or players who have been subbed off for tactical reasons will be able to replace the sent-off player, who will not himself be allowed back.

In other words, while the sanction for the offending player remains the same, his team will only be a man down for 20 minutes. The aim is to redress the imbalance which red cards have often brought about and ensure that the match remains a more even contest.

The Captain’s Challenge will allow teams to call for one decision - for try-scoring or foul play, or for anything at all in the last five minutes of a game - to be referred to the TMO. Teams will be limited to one incorrect challenge apiece - as in tennis, a correct
challenge will mean that teams can still make another.

Challenges can only be made up to 20 seconds after the referee has stopped play, and can only refer to the passage of play immediately preceding that stoppage. Set-piece decisions cannot be challenged, and in all cases the referee’s decision will remain final.

Goal-line drop-outs will restart games when an attacker has been held up over the line, the ball has been knocked on in goal, or when a defender grounds behind his own line following a kick through. The drop-out can be made from anywhere on or behind the goal line and must be taken immediately. 

The kick must go at least five metres - if not, the non-kicking team can either ask for it to be retaken or opt for a five-metre scrum. When a penalty or drop-goal attempt is missed, play will still be restarted by a drop-out by the defending team from the 22.

The three trial measures were proposed by the PRO14’s sports and regulatory committee and have been approved by World Rugby. Edinburgh’s match at home to Zebre next Friday night will be the first time a Scottish team plays under them, while Glasgow’s initial experience will be in their match against Benetton in Treviso the following afternoon.