You know... as a fellow card player.  A deck of cards is one of the great analogies to a bitcoin key.  In fact a (well) shuffled deck dealt out offers 232 bits of entropy.  Just a few bits shy of a 24 word seed!  It can actually produce a 21 word seed.

But people do not realize how fantastically many possible combinations of a deck of card has (52! or ~8e67) In fact, did you know that it is EXTREMELY unlikely that a properly shuffled deck will repeat a sequence ever dealt from another properly shuffled deck?  As in, ever? 

For fun I actually dealt this sequence from this deck of bicycle cards sitting next to me:

6h9sQd2c5hAd4c7hTsKd3c8sJdAc4h7c9hQs2d5c8hJsTdKc3h6s9dQc2h5s8dJcAh4s7dTcKh3s6d9 cQh2s5d8cJhAs4d7sThKs3d6c 
-or-
6♥ 9♠ Q♦ 2♣ 5♥ A♦ 4♣ 7♥ T♠ K♦ 3♣ 8♠ J♦ A♣ 4♥ 7♣ 9♥ Q♠ 2♦ 5♣ 8♥ J♠ T♦ K♣ 3♥ 6♠ 9♦ Q♣ 2♥ 5♠ 8♦ J♣ A♥ 4♠ 7♦ T♣ K♥ 3♠ 6♦ 9♣ Q♥ 2♠ 5♦ 8♣ J♥ A♠ 4♦ 7♠ T♥ K♠ 3♦ 6♣
-or-
then viable coral multiply puppy inquiry clap camera rebel smile fish tackle pull pledge regular embark session inner select knock furnace

The first address in the BIP44 sequence would be 12hZ1awWPMo4tGfYeHqZL2bhJr3DRafsqK (or bc1qpfaa7ms34k42jwl8eymdnxxcm2hug7d35dvp3q if you want to save on fees).  You can use this seed along with the password I made you!

If one were traveling to another place and needed a way to transport a private key in a very inconspicuous way one could just have a deck of cards in their luggage in a specific order.  And it would have just as much randomness as a 21 word seed phrase.

Not suggesting people use cards to store their seeds.  Too fragile, and abstracted.  But still a possible thing.