Pig is played for 10 rounds. Each round, you roll two dice and add the numbers rolled, unless you get doubles, then you multiply. You can stand and keep rolling to build up your score, or you can sit, choose to stop, and keep the points you’ve earned that round. If you roll a 1 on any die, you lose all the points you earned during that round, and the round ends. After you stop, your turn total is added to your overall score, and the next round starts.
Introduced to me by my 8th grade Geometry Teacher.