Fortree City

A woman in one of the houses of Fortree City will give away TM10 (Hidden Power) if the player can guess which hand she is hiding a coin in three times. Also in Pokémon Emerald, in this same house there is an old man who will teach a compatible Pokémon Sleep Talk one time only.

A boy in one of the houses will trade his Skitty (nicknamed Skitit) for a Pikachu in Pokémon Ruby and Sapphire, and his Plusle (nicknamed Pluses) for a Volbeat in Pokémon Emerald. In Omega Ruby and Alpha Sapphire, Elyssa will trade her Skitty (nicknamed Skitit) for a Spinda.

In Pokémon Ruby, Sapphire, and Emerald, there is a shop in the southeastern corner of Fortree City that sells a variety of Secret Base decorations. There are two counters, the one on the left is selling desks and the one on the right is selling chairs.

Desk shop
Small Desk 3000	Pokémon Desk 3000
Heavy Desk 6000	Ragged Desk 6000
Comfort Desk 6000	Brick Desk 9000
Camp Desk 9000	Hard Desk 9000

Chair shop
Small Chair 2000	Pokémon Chair 2000
Heavy Chair 2000	Ragged Chair 2000
Comfort Chair 2000	Brick Chair 2000
Camp Chair 2000	Hard Chair 2000

In Pokémon Omega Ruby and Alpha Sapphire, the Secret Base decoration shop is replaced with the Secret Base Guild. This is where the player can meet and battle Aarune, and also serves as a place to buy Secret Base decorations from. Some items are only available after the player has achieved a certain rank for their Secret Base team.

Lass
Small Chair 1,000	Poké Ball Chair 1,000
Heavy Chair 1,000	Soft ChairBronze 1,000
Rough ChairBronze 1,000	Brick ChairSilver 1,000
Log ChairSilver 1,000	Hard ChairSilver 1,000
Small Desk 2,000	Poké Ball Desk 2,000
Heavy Desk 3,000	Rough DeskBronze 3,000
Soft DeskBronze 3,000	Brick DeskSilver 4,000
Log DeskSilver 4,000	Hard DeskSilver 4,000
Icy DeskGold 5,000

Schoolkid
Fence 500	Makiwara 1,000
Tall Grass 1,000	Gym Statue 3,000
Boppoyama 4,000	Invisible DollGold 4,000
Comfortable Bed 6,000	Vending MachineSilver 6,000
Glitter Mat 2,000	Jump Mat 2,000
Spin MatBronze 2,000	Pitfall MatBronze 2,000
Square-One MatSilver 2,000	Red Spin Panel 2,000
Blue Spin PanelBronze 2,500	Yellow Spin PanelSilver 3,000
Red Warp PanelSilver 2,500	Blue Warp PanelGold 2,500
Yellow Warp PanelGold 2,500	Toy PCBronze 5,000

Main article: Fortree Gym

The Fortree Gym is the official Gym of Fortree City. Fortree's Gym Leader, Winona, uses Flying-type Pokémon. When defeated, she awards the challenger the Feather Badge, which allows the player to use Fly outside of battle, as well as TM40 (Aerial Ace) in Pokémon Ruby, Sapphire, and Emerald and TM19 (Roost) in Pokémon Omega Ruby and Alpha Sapphire. Fortree Gym is inaccessible at first due to an invisible Kecleon blocking the path; the player must use the Devon Scope, given to the player on Route 120 by Steven, to gain access to the Gym.

In Pokémon Ruby and Sapphire, Fortree City's has a total population of 36, making it a medium-sized city by Hoenn standards.

In Pokémon Emerald, Fortree City's has a total population of 39.

In Omega Ruby and Alpha Sapphire, Fortree City has a total population of 37.

Fortree City debuted in Short Shift for Shiftry, where a meeting between the Gym Leaders of Hoenn took place there. Although Flannery had been the one to arrange the meeting following Mt. Chimney becoming dormant, it was held in Fortree due to Winona being responsible on supervising the other Hoenn Gym Leaders. Tate and Liza were unable to attend the meeting, due to them having to guard the Red and Blue Orbs on Mt. Pyre. Wallace, who was attending business in Fallarbor Town, participated the meeting via webcam. The Gym Leaders voted on whether to side with Team Magma or Team Aqua, but Norman refused to cast the deciding vote, choosing to remain neutral, and proceeded to leave the meeting.

In I Dare Ya, Altaria... Knock Chic off My Shoulder, Sapphire arrived in Fortree and challenged Winona to a Gym battle, only to be defeated, although Winona did agree to coach her. Soon after, Ruby arrived in Fortree as well with Wallace. Ruby and Sapphire wound up getting into an argument, following which Ruby left Fortree on his own in Master Class with Masquerain, forcing Wallace to chase him. Sapphire, meanwhile, trained with Winona until she earned the Feather Badge.

In The Beginning of the End with Kyogre & Groudon II, the Gym Leaders learned of the tsunami that had flooded Dewford, Slateport, and Littleroot, following Kyogre's awakening. In The Beginning of the End with Kyogre & Groudon III, Groudon's awakening caused Fortree to be struck by a massive heat wave, withering all local plant life. The Pokémon Association Chairman subsequently ordered all the Gym Leaders present to head out to deal with the threat.