There's something alluring about what a card game does to people: it attacks their ego, their sensitivity – and their wallet. Cézanne understood this when he painted these peasants playing cards in 1890s Aix-en-Provence. Using shadows and shades of blue, he creates an incredible atmosphere of stillness and concentration. The men are looking down at their cards, rather than at each other: you get the feeling they don't have much to talk about. These were men who worked off the land, and the only way they could communicate outside work was through playing cards.
Back then, cards weren't mass-produced, so it's likely they're using a hand-painted 32-card deck called a "piquet". Around 1850, a very famous Austrian magician called Dr Johann Nepomuk Hofzinser started hand-painting such decks, and soon became a pioneer of sleight-of-hand tricks. I can't see any cheating going on in Cézanne's paintings, though: they're not even playing for money.
The players have seven cards in each hand, so I'd say they're playing a version of gin rummy. That's a refined, subtle game, which is why the paintings feel so still and quiet. Bridge and cribbage are still played like that today, but with other card games the stakes can run to millions. The atmosphere is very different. Texas Hold 'Em, for instance, is an aggressive poker game: you have nine people at a table (including some very beautiful women, whose high sexual energy is there to distract), and the atmosphere is electric. Poker players also often wear dark glasses or wide-brimmed hats so you can't see their faces. If Cézanne were around today and painted a poker game, we'd get a very different picture.