Nintendo's first mobile game, "Miitomo," was released in March 2016. Nintendo

After the relative success of "Miitomo," Nintendo's next forays into the competitive mobile gaming sphere will be the first real test for the company as it enters a new market. The new games in the "Fire Emblem" and "Animal Crossing" worlds will be free-to-play, the Wall Street Journal reported Wednesday. The two games will feature in-app purchases, but Nintendo did not reveal details on how it will monetize the franchises.

"Fire Emblem" and "Animal Crossing" will be released in the fall, Nintendo revealed during its earnings report in April. Both games feature dedicated fanbases, which make them ideal candidates to expand Nintendo's smartphone game portfolio. "Animal Crossing: New Leaf," released in 2012, sold 10 million units, while "Fire Emblem Fates," released in February, was the series' biggest U.S. launch, with more than 300,000 copies sold in its first three days.

The two games also target important demographics with opportunities for monetization. "Simulation RPG with character customization and tactical elements, globally loved by fans since the first launch in 1990," is how DeNA describes "Fire Emblem." "Popular series among consumers, especially female and young people, with over 10 million units sold for both DS and 3DS," reads the description for "Animal Crossing."

After announcing its plan to release smartphone games in 2015, Nintendo held off from using beloved properties like "Mario" or "Zelda." "Miitomo," Nintendo's first smartphone game, was released in March 2016. The social game connected players to their network of friends, with rewards being earned by answering questions or completing daily tasks such as changing a costume. "Miitomo" has been downloaded 10 million times since its launch, but Nintendo has not revealed the exact revenue earned from the game. An earlier report from SurveyMonkey Intelligence estimates "Miitomo" earns $280,000 a week in revenue.

"Fire Emblem" and "Animal Crossing" will be the first "pure game experiences" for smartphones from Nintendo. Costume or character packs could be among the in-app purchases. One of the key components of "Animal Crossing" is the use of the Nintendo 3DS' internal clock that determines when stores are open or closed, when animals appear or when certain tasks can be completed. Costumes and home furnishings within the game could also be monetized.