Definition: Play It Again Sam is often just another name for No Alibis. In this version, handicaps are converted into, essentially, mulligans. If you are a 14 handicap, then you'll get 14 chances during a round to re-play a stroke. (See No Alibis link above for full explanation of this version.)
However, Play It Again Sam is also often a term used for a game that is sort of the opposite of No Alibis. Instead of each golfer being able to replay his or her own strokes, in this version of Play It Again Sam your opponent gets to make you replay strokes.
Hit a fantastic approach to within inches of the cup? Your opponent can make you hit it again. Sink a long putt? Your opponent can call "do over."
This version is best played among good friends, for obvious reasons, and is only well-suited to groups of players of similar abilities. Also, it is advisable, in the interest of time, to limit the number of strokes that are re-playable.
