In our school it’s a new fad that many girls are playing with poker cards (like the deck that has king, queen, jack, ace, etc.). Whats the deal with them? Are they OK to play with? Is there a source that says they are not?
The Kedushas Levi writes (in Derushim L’Chanukah) that these cards have Tumah on them and they should not be played with.
Some associate this with the fact that they are intended for gambling, or because of the pictures on them. Alternatively, because the cards are considered to be tools designed to cause Bittul Torah.
Whenever it is not an issue of Bittul Torah, Uno cards and other playing cards would be permissible to play with, and that is indeed the common custom.