It was never Professor Plum in our house. The professor was entirely innocent. He was in the clear. Perfect alibi. Water tight. He was doomed for eternity to be one of the good guys.
I don’t know when we lost the card for Professor Plum, but it changed the way we all thought about him. With no Plum card in the deck to start with, he simply couldn’t end up in the murder envelope. He couldn’t have done the crime! But we still had the counter, so Plum was still physically there in the house when it was time to investigate. This situation gave him a kind of purity. Everyone else was under suspicion, but Plum? Plum was always on the side of the angels.
When I bought my own Cluedo set a few years back, I immediately ditched the Professor Plum card it came with so that the experience would mirror my experience of playing the game as a kid. Five children in my house growing up, and all of us clumsy and careless. As a result, we played Scrabble with missing vowels, we played Monopoly with limited liquidity. We played a version of Cluedo in which it was never Professor Plum – in which it would never be Professor Plum.