I designed Embargo in 2006, inspired by a two-player kind of Chinese Checkers called Halma. The rules below are from an adaptation you can play online at ItsYourTurn.com.
For simplicity's sake, this is a two-player version. You can play with up to four players, too, each player taking control of one of the four corners. You can play this on a regular chess board with generic tokens moving along the lines and vertices of the grid.
The object of Embargo is similar to Chinese Checkers: move all your pieces from your "yard" (the spots where your pieces start) to your opponent's "yard". Your yard is the light-colored section of the board where your pieces are initially placed.
The pieces are initially set up on opposite corners on a 9x9 board. The screen shot below shows the starting position for Embargo:
Pieces move along straight lines for any number of empty spaces, like chess rooks.
Pieces cannot move through Walls (see the "wall" section below), except when Tunneling (see the "tunneling" section below).
When two pieces of the same color line up in a straight line, one or more walls can form. Pieces cannot move through walls of either color, except when tunneling. In other words, a wall blocks pieces of both colors from moving across it.
When you have a move that either SHORTENS or EXTENDS your own wall, those moves are legal. (See example below.)
The picture on the far left shows the beginning position of the board, before any moves are made. The middle picture shows an example of a move EXTENDING a wall. The right-hand picture shows an example of a move SHORTENING a wall, which is legal.
When you make a move that SHORTENS a wall and goes through a perpendicular wall at the same time, that move is legal and is called TUNNELING. It just means that you have moved your piece through a perpendicular wall as you shorten your own wall at the same time. (See example below).
When you tunnel, you can also choose to "bust" a wall, by landing in between two pieces that form a wall. The example below also shows a "wall busting" move being made.
The picture on the far left shows the piece chosen to do the tunneling. In the middle picture, the green piece has TUNNELED through the orange wall, to emerge on the other side of the orange wall. Green is able to do this because this is a move that shortens the green wall. In the right-hand picture, The green piece has landed IN BETWEEN the two orange pieces forming a wall, and has BUSTED the wall. The two red X's show where the orange wall used to be.
This move can only be made when you are shortening a wall. If the green piece had not been part of a green wall, it would not be able to move through the orange wall like it did above.
The 25 move rule:
If you have a piece left in your yard on or after the 25th move, then you automatically lose the game. Make sure all your pieces are out of your yard by the 25th move of the game.
Winning the game:
You win the game when all your pieces are in the enemy yard.
Key strategic point:
You always want to make sure that you have at least one piece deep in enemy territory very early in the game. You can then use this piece as an anchor to pull your other pieces through the tunnel to the enemy yard. If you neglect to put a piece in enemy territory, it's quite possible that your opponent can build an impenetrable wall across the middle of the board that you can't cross.