Some categories, such as three-card poker and five-cent machines, saw year-on-year drops in revenue of between 6% and 8%.
However, a number of segments enjoyed revenue increases, with the biggest percentage growth coming in bingo. It rose 24% to $17.9m.
Sports wagering also grew 21% to $301m, while revenue from roulette games rose by 5% to $384.1m.
In terms of total amounts, twenty one generated the highest sum of revenue within the games segment ($1.15bn), while one-cent machines took the most in the machine category ($3.33bn).
For the month of December alone, Nevada generated $1bn in gaming revenue, a 4% increase.
Machines accounted for $635.8m of this revenue, while sports wagering revenue rose 28% to $44.1m.
Nevertheless, the game twenty one saw an 11% fall to $89.4m in revenue for December, while baccarat dropped 15% to $102.8m.