What strange chess rules can you think up?

Race to Zero.

There's no new moves added to pieces. Simply both players attempt to lose all of their pieces as quickly as possible. (except the King) Checks still force the King to Move, but Checkmates result in the "Checkmated" person to win, so avoid that I guess. (I haven't thought over that one part too much, feel free to change it!) If you have the opportunity to take a piece more than 2 turns, your piece is forced to take it. Example: White moves a Knight C6, Then Black has a pawn on B4. Unless Black moves the Pawn, two turns from then White's move is automatically forced to take Black's Pawn. 

pawns promote to kings.there are no knights,bishops,rooks and queens

king of the hill,too

Here's a strange rule, though faulty code thought it up, not me. If it is stalemate, it is checkmate, and either way, you can keep playing. The opponent cannot play any moves, and you can play as many as you want. As long as it's mate, the king can be captured. This resumes play, and the last piece left on the board (excluding pawns) becomes royal. It cannot make any moves that would result in it being lost. If it has no moves left, it's checkmate once again. If that piece is captured, it's still checkmate (though the faulty code allows you to keep playing beyond this point, where the game becomes significantly buggy, specifically on a8 and b8).

Once your piece touches the end of the chessboard it's now your opponent's piece and they can now control it. 

If you spend $999,999,999,999 on the chess set you are using, you can use a atomic bomb (which comes with your set) on your opponent's king :)

Creeper piece. at the start of the game, a pawn of the player's choice is replaced with a creeper. when that piece is captured it explodes and all pieces within 2 squares are removed. if a king is within that range it counts as a checkmate for the other player. if both are, it's a draw.

7.8.8: A player may purchase snacks from the arbiter by giving up either:

a) fifteen (15) minutes of their time, or:

b) 2 points of material

-Note: A player may provide a piece of larger value and receive change in the following ways:

1 bishop -> 1 pawn

1 knight -> 1 pawn

1 rook -> 1 bishop/knight (player's choice)

1 queen -> 1 rook + 2 pawns

A player may not purchase snacks if they do not have the required material and time.

Snacks are limited to whatever the arbiter has on hand.

I just have one question. WHAT???

Extreme Chess: For every piece that your opponent captures, you will have to do something extreme (bungee jumping, skydiving, sour candy, etc). Depending on what piece is taken, this determines what extreme thing you will do. If you get checkmated, you must do something really crazy, and backing out will ban you from chess for 1 week.

Pressured Chess: For every move that is made, the person will feel a little bit of pressure on their neck. If your opponent captures your piece or puts you in check, the pressure increases. You can stop the pressure if you want, but then you lose. Also, doing an illegal move will add an insane amount of pressure.

Sleeping Grandpa Chess: For every piece that is captured or every time you are put in chess, you must visit the sleeping grandpa and wax his legs. If your queen is captured or your opponent promotes, you must pour a bucket of slime on him. If you wake him up, you lose the game.

Is that the same as giveaway chess?

Why do I feel like someone is going to say,

British Chess: Like chess, but with no queen.

Pac-Man Chess: You can move your piece to an imaginary square off the edge of the board, teleporting it to the opposite side of the board.

Checkers Chess: You can only move forwards, until you get to the other side of the board then you can move forwards and backwards. Also, rooks, bishops, queens and pawns (only on their first move) can jump over an enemy piece and capture it.

Clue Chess: Before the game starts, you must pick 2 pawns, a weapon for each of them, and a room for each of them (the rooms will be right outside the board). Your opponent cannot know, and you must tell the judges so they will know if you were lying or not. If your pawn promotes, you get to hide in a room and use your weapon once you are ready. You can only use it once, and when you come out of the room, you can only move like how the piece you promoted to would. (For example, if you promote to a queen, you must exit this room through one of the doors and move like a normal queen). Each weapon has its own gimmick. For example, the revolver would shoot another square, or the candlestick would burn a 2x2 area of the board for 1 turn, and other pieces cannot move there (you can only shoot the revolver in areas that you cannot simply go to in 1 move, and it cannot take the king. So a queen cannot shoot the revolver directly ahead of her. And the burned 2x2 area must be 1 space ahead of you). You can only use this weapon once. And you can make your move before using the weapon, but it has to be in the same move. If there are no promotions, it is just a normal game of chess.

You forgot about knights and kings.

Here's why I excluded them.

Because of a knight's crooked movement, it is unclear which space exactly it is jumping over.

Kings can only ever move 1 square. Also, I forgot to mention: Sideways movement, including castling, is not allowed until you get to the other side of the board. Therefore, castling is not allowed.

I like your point, but why do pawns jump over pieces?

Because why not?

fair enough.