Give me an idea for a brand new chess variant. I’ll start. All moves are legal, even if they put yourself in check. If you are putting the other person in check, they don’t need to know. You win by capturing the king
Here’s an idea: two different chess pieces can combine into one piece! For example, you could combine the knight and queen to make a piece that can’t be captured unless a fork, pin, skewer, or blunder happens. They could also combine the queen with the king to make it very hard to be checkmated!