What symbolism does a deck of playing cards have in the faith. I know that a few of the Lwa are card players and gamblers but is there a game that they like to play?
Playing cards are the main form of divination in the religion; houngans and manbos can ask the lwa to speak via the cards during what is called a leson/literally 'lesson'. In asson lineages, priests are taught how to read cards as part of their initiatory process and are given the specific meanings assigned then; some are general and fairly common throughout the religion, and some will be more specific to the particular peristyle.
Some of the lwa are definitely gamblers, but I haven't seen them play cards. Kazino (KAH zee know) is a pretty popular card game in Haiti, and I imagine the card-playing lwa might like that...but beware gambling with the lwa! You might end up handing over a little more than you intended or might end up with a debt that maybe money can't pay off.....
My experiences with the lwa and playing cards has all been around them giving me a leson or showing me something they would like me to know about giving a leson for clients.
Super interesting question, and I hope my answer helped...let me know if I can clarify anything!