The club has received several requests to explain how the shortened form of the game is adapted within the laws of Rugby Union. Here goes:
The number of Players
Teams nominate a squad of twelve players. Seven play at one time, and three replacements are permitted per game. The only time a replaced player can return is for a blood injury.
The games will be seven minutes each way, with the timekeeper stopping the clock when instructed by the referee. Half time is no more than two minutes.
Conversion kicks have to be drop kicks, with the kick taken within forty seconds of the try being scored. A kick is disallowed if this time limit is exceeded. The defending team have, as usual, to stay behind the goal line until the kicker moves to take the kick.
If shown a yellow card, the period of suspension is two minutes.
Offences at Kick off or re-start kicks
A free kick is awarded to the other side.
Three players per side form a scrum
Penalties & free kicks
Any player may take a penalty or free kick awarded for an infringement with any kind of kick: punt, drop kick but not a place kick. The ball may be kicked with any part of the leg from below the knee to the toe but not with the heel.
If a kicker indicates to the referee the intention to kick at goal, the kick must be taken within thirty seconds of the penalty having been awarded. If the 30 seconds is exceeded the kick is disallowed, a scrum is ordered at the place of the mark and the opponents put in the ball.
Here are the IRB laws for Sevens in full .