Here is my idea for a chess variation:
It's like Crazyhouse, but instead of capturing pieces to get reinforcements, you start the game with 2 Knights, 2 Bishops, 2 Rooks, and 1 Queen in reserve.
Captured pieces are removed from the game.
Your reserve pieces can only be dropped on each piece's starting square (example: white knights drop on b1 or g1) and only if you are NOT in check AND dropping a piece does NOT give you more than 2 knights, or 2 bishops, or 2 rooks, or 1 queen on the board. If you have 1 bishop on the board, you cannot drop a reserve bishop on the same color.
You may not castle with a dropped rook.
It's like Crazyhouse, but instead of capturing pieces to get reinforcements, you start the game with 2 Knights, 2 Bishops, 2 Rooks, and 1 Queen in reserve.
Captured pieces are removed from the game.
Your reserve pieces can only be dropped on each piece's starting square (example: white knights drop on b1 or g1) and only if you are NOT in check AND dropping a piece does NOT give you more than 2 knights, or 2 bishops, or 2 rooks, or 1 queen on the board. If you have 1 bishop on the board, you cannot drop a reserve bishop on the same color.
You may not castle with a dropped rook.