The king might be weak, but what if it was even weaker? Wishlist Deckmate on Steam! store.steampowered.com/app/23... Join the discord server for more info! / discord
I think this can make for a potential new variant: Prisoner. Each side has an opposite colour king in the cage, they can't move. When checkmate is delivered, it's actually pieces saving a prisoner
It feels like the best way to play this might be with aggressive pawn movement. Because the pieces are the only ones that can move flexibly back and forth to protect the king and deal with threats I feel like they are best staying behind an aggressively expanding pawn structure until they clash and simplify and then it’s a race to exploit any resulting weaknesses.
Would love to see you cover Xiangqi/Jianggi palaces in conventional chess, or far older middle eastern variants where the king may make one knight move per game in a similar role as castling. Similarly, if other pieces were allowed greater options for their first move, like the pawn double step being granted to the knight for one move only, or if the bishop could "castle" with the pawn directly in front of it and switch places.
an idea for you: capture the flag(king). it is dropchess where you can place captured pieces back on the board, kings can't move. you win by capturing a the king and then returning the capturing piece back to your king (which you can move onto with your piece which is caring the enemy king). you probably need to balance which pieces you have on the board and the board size or it could last forever
alternatively when you capture a piece caring your flag(king) you are now caring it and need to return it to its start square. though this could lead to like... a strat where your queen picks up your king and just runs around with it for the entire game
the king isn't the weakest piece in chess it's on par with a knight, arguably a bit better. The reason it's best to barricade it is because it's a loss condition. If it didn't lose you the game to lose it it'd actually be a pretty important piece to use.