How to make make objects or tokens collidable?

Hello, In my DnD game, I implement a lot of puzzles.  I have a great puzzle in mind for a future game.  It will require the players to move blocks around, in order to create a path into a secret room.  The blocks will be similar to some of the blocks you see in tetris.  Here is specifically what i want the blocks to do: 1)  I want them to have a boundary, which will be their edge. 2)  The boundary will collide with the other blocks in the puzzle, meaning that they CANNOT overlap. 3)  The blocks will be within a fixed area. 4)  I want the players to be able to move the blocks, but the blocks will only be able to move into a space if it has a clear path to that space.  5)  Most important, a block can only move into a space that can accommodate it's dimensions.  Again think Tetris. Any advice would be helpful.  thanks!

First off, you might look at some of the "Traffic" puzzles for inspiration.   Second, without the API, there isn't a way you can automate this.  If the puzzle pieces are blocking sight, you could have a copy of them on the objects layer which players can move, but you manually move the blocking copy on the DL layer when the move is validated.