The players take turns in joining dots according to simple rules, until one player cannot make a move.
Start by drawing two or more spots on a piece of paper.
Players then take turns to make a move, according to the following rules:
- Draw a line joining two spots, or a single spot to itself. The line must not cross another line or pass through another spot.
- Draw a spot on the new line.
- No more than three lines can emerge from any spot.
The last player to be able to move wins.
The game is remarkably complicated, and even starting with two spots leads to an interesting game.
In the following sample game with two spots Blue has the first move, and Red wins after 4 moves because Blue has no move:
Sprouts was invented by the mathematicians M. S. Paterson and John H. Conway, and was described and analysed in Berlekamp, Elwyn R., John H. Conway, and Richard K. Guy (1982), Winning Ways for your Mathematical Plays - Volume 2, Academic Press, ISBN 0-12-091102-7, pp. 564-568.