Has this been done already?
My latests board game design involves lots of effect cards that can stack and modify the card(s) before it. Example: play a "move two spaces" card with "double" stacked, followed by "triple" and then a "repeat" card. Creating a possible 24 space move (board has 200 spaces). The next player could start with a "mimic" card to copy the cards played by the previous player.
All cards in the game can be played on either yourself or another player. All cards "should" be able to interact and modify another card in your hand if you combo them.
Has there already been a game on the market like this one?
Anyway, some of the board spaces have effects too as do the pieces "avatars" used by the players to move around the board.