There are a great many variants that are possible.
Equal Women's Rights chess:
The queen is reduced in mobility to the same as a king. No more of that wonder woman crap... Castling rules apply to the queen the same as if it were a king. Mating either king or queen is a win.
Affirmative action chess:
White starts out normal. White plays normal chess. White has first move. Black has no army at all on the board. Black has a full crazy house army in the pocket. Each piece and pawn may be dropped 1 time for black. (8 pawn drops 1 queen drop 2 knight drops 2 bishop drops 2 rook drops)
Pawn Grubber Chess:
The same as normal chess in terms of piece setup and movement, and rules. The only difference is the king is no longer important. Checkmate is not a thing. Winning all 8 enemy pawns is the only way to win.
Equal Women's Rights chess:
The queen is reduced in mobility to the same as a king. No more of that wonder woman crap... Castling rules apply to the queen the same as if it were a king. Mating either king or queen is a win.
Affirmative action chess:
White starts out normal. White plays normal chess. White has first move. Black has no army at all on the board. Black has a full crazy house army in the pocket. Each piece and pawn may be dropped 1 time for black. (8 pawn drops 1 queen drop 2 knight drops 2 bishop drops 2 rook drops)
Pawn Grubber Chess:
The same as normal chess in terms of piece setup and movement, and rules. The only difference is the king is no longer important. Checkmate is not a thing. Winning all 8 enemy pawns is the only way to win.