Leap-Frog is a game for two or more players in which the object is to capture the most pieces from a board containing identical pieces.
To play you will need a gridded board (A History of Board-Games Other Than Chess (p. 93) suggests 15×15 to 18×18 squares), and enough pieces to fill all the spaces on it. All the pieces are the same.
Place one piece on each square of the board.
To start, the first player removes one piece and places it in front of themselves. After this, the players take turns by jumping a piece (not diagonally) over another into an empty space, and capturing the piece that was jumped. Multiple pieces may be jumped in a turn, even changing direction, and the player must capture as many as possible with the piece that was moved.
The game ends when no more captures can be made, and the player who captured the most pieces is the winner.
Murraya[pp. 93–4] invented a variant in 1898. The undifferentiated pieces are replaced by pieces coloured white, yellow, red, and green, in the ratios 4:3:2:1. The pieces now count points according to these ratios (i.e. green is worth 4 points while white is worth 1). To set up the board, the pieces are arranged randomly on the squares, and the first player must remove a white piece to begin. The player with the highest point value of pieces taken at the end wins.
Another way to vary the game would be to play on a non-square or non-uniform board.
Take It Away is a similar game by Sid Sackson.
Murray, H. J. R. (). A History of Board-Games Other Than Chess. Oxford University Press: Oxford, England, UK. ISBN: 0-19-827401-7.