Playing Poker With Tarot Cards
Assumption uses the minor arcana of a Tarot deck, which means that you'll be dealing with Knights in addition to the standard Kings, Queens and Jacks (Pages). It's possible for you to use regular playing cards for this game by adding doctored Jacks from an identical deck for your knights. In fact, Powers was too superstitious to mess with a Tarot deck, so he used a modified playing card deck to figure out the hands he'd need to use in the novel.
I participated in an Assumption game once; we set it up as a joke to spook Tim at Clarion the week he was leading the writing workshop. His wife Serena saw us playing with the tarot cards, shook her head and said to Tim, "See, if you put it in a book, the kids are going to try it."