Definition: A Murphy is a side bet that can be invoked by a golfer who is chipping to the green. The player declaring "Murphy" is betting that he can get up and down in two strokes.
The bet amount must be decided before the round; also, players should agree before starting the round if the issuing of a Murphy means it is automatically accepted by the other players in the group, or if the other players get to decide individually whether to accept the bet.
And make sure everyone agrees on the area from which a Murphy can be declared. A Murphy can never be declared for a ball on the green, and most groups rule out balls on the fringe, too.
