A game of chance, or a divination tool? The Mexican card game known as Lotería has a long colorful history, as a version of bingo that just needs a deck of cards, a board, and some chip pieces. For those who play, it’s a fun evening. But as folk art, it is even more fascinating. The deck of cards portrays characters like a magician, a beautiful lady, or a soldier. But like the tarot deck, it also has icons that are both quotidian and strange, filled with hidden meanings, for example, a melon, a ladder, a boot, or a flowerpot. And then there’s a devil, a mermaid, and a drunk guy “El Borracho” (many people’s favorite.) The history and the art of Lotería decks make up the small but very fun exhibit “Lotería! Mexico’s Game of Chance and Poetry” at Casa Dolores, through Sept. 27.