"It was another rowdy night at the tavern. Sirin made his way though the throng of drunken patrons, intent on finding a game of Atsar in the hope that he could replenish his dwindling funds."

Almost every sword and sorcery or epic fantasy novel I've read has had a scene like this. In fantasy, a gambling den offers numerous plot variations that writers can utilize to enrich their novel. Gambling games, be it using cards or dice, are good devices that, in the hands of a savvy writer, can become a unique trademark of a novel or series.

Point

A gambling game should be a part of a larger plot point. Be it a means to showcase a character's sudden luck or a way for a character to show off his sleight of hand, there must always be a point when including a card or dice game in fantasy novels. Astute writers know to veer away from classic tropes and try to find new and creative plot uses when dealing with gambling games.

Rules

All games have rules and it can be a challenge for writers to create an entire game from scratch and append it to their fantasy world. It is sometimes easier to modify the rules of existing games to make a fantasy gambling game that is familiar enough for readers to easily grasp yet different enough to provide novelty to a novel. Rules should be clear on how one would win and how one would lose. Rules can also be a handy way to showcase how a main character is intelligent enough to discern and utilize a loophole to come out on top. Complicated rules should be described carefully, so as not to lose the reader's attention.

Stakes

Gambling is a good way to add suspense to a novel. The higher the stakes, the more invested the reader becomes. The best writers utilize stakes that serve as a focal plot point. Be it a large sum of money that is much needed for an expedition to start, or even the life of a main character, the right stakes can help heighten tension in a novel and can even be a means to start off a plot twist that can affect the course of the entire book.

The addition of gambling games to a fantasy  novel adds another layer to the world that the main characters are living in. It is natural for people to be drawn to the excitement that putting valuable things at risk for the chance of a payoff brings. Fantasy writers would do well to build upon this and use it to draw the reader's attention. The use of gambling games can make readers, within the span of a few paragraphs, live in the moment and feel the excitement risk taking brings. As a plot device, card and dice games can inevitably showcase an author's prowess at world building and serve as additional affirmation that a reader is truly immersed in a different and unique fantasy world.