3D chess was all holographic. Prove the opposite.
Charlie Evans melted the chess pieces in Charlie X.
From the "For What It's Worth" Department:
The script for "Chalie X" has an interesting quick scene between Kirk and McCoy right before Charlie comes to Kirk's quarters for the above scene. Before Charlie gets there, Kirk is puzzling over the inexplicably melted chess pieces and tells McCoy: "These are Antarian metal chess pieces. They can't be melted." (I guess the thinking was that crossing your eyes with dramatic sting music and melting stuff at will is rather hum-drum. But--Holy Moly!--he's able to do that with unmeltable
Antarian chess pieces! How could he have done that
just by crossing his eyes with the dramatic sting music? Now that
ability should be concerning!)
In the end, of course, the whole scene was excised.