The game of Weak! is played with normal chess rules, but with a very special opening setup. While white has its normal array, black has a King on e8, seven Knights on the back row, 8 Pawns in the usual places, and 8 extra Pawns arranged as he pleases on his third and fourth ranks.
 
You start as Black placing the 8 extra pawns. Then the computer opens with a white move.
 
 
The name of the game is a play of words. There are seven nights in a week and seven black knights in the game.
 
This game is attributed by Pritchard to Ralph Betza, and said to be invented in 1973. However, Ralph Betza says about this game that he probably didn't help to invent Weak!.