Full House

Fullhouse was created by Topher Gayle in 2004. It has been in play for over a year at schemingmind.com.

Setup

Fullhouse uses the standard chess board, piece movement rules, checking and checkmate rules. The initial board layout is the same as regular chess.

However, a second set of pieces (less the kings) is held in reserve at the sire of the board. 

The first 15 moves of the game involve the players placing these pieces on the unoccupied squares of the board alternately, starting with white. The only restriction is that kings may not be checked at this stage of the game. Thus a white knight is not allowed to be placed at F6 or D6, nor is a black knight allowed to occupy F3 or D3 at this point in the game.

The outcome of many, if not most games, is decided by the strategic placement of pieces during this phase of the game.

Pieces

Two complete sets of pieces (less one king of each color) are needed to play FullHouse.

Rules

Once all the pieces are placed, play proceeds exactly like regular chess. The first several moves are unrelentingly bloody and wild.

Notes

On inspection, it becomes clear that black has a vulnerability at F7. So far, in more than a year of playing this variant at schemingmind.com, it has not been proven that there is a forced win for white.

Note that if white opts to attack in another place than F7, then white discovers their own vulnerable spot at F3!

Fascinating games have been played by players who agree to (initially) ignore the vulnerable spots.