Well, there are lots of different suits for cards in real life..
Do we know what kind of cards NPC's usually play with for gambling and such in the Forgotten Realms?
According to the Forgotten Realms Campaign Setting (a 3rd Edition source book) and Aurora's Whole Realms Catalogue (an AD&D source book, as well as an in-game catalogue for selling items by mail), the commonly used Talis deck has fourteen (FRCS) or twelve (AWRC) cards in each of four "elemental" or "planar" suits (flames, stones, waves, and winds), plus twenty-two "trump" cards called "major arcana" (Sun, Moon, Star, Comet, Throne, Key, Night, etc.). It is used for games called whist, poker, talison, elemental empires, and old wizard, among others.
In effect, it is a standard Tarot Deck with the names changed.
Wizards also created 3 Dragon Ante, a real life card game which was also intended to be seen as an in-world game. I have had players play 3 Dragon Ante in character at the table, and actually break out the card game at, you know, our table. It makes for fun, immersive roleplaying with the right group.