Two new mechanics, Dynamax and Gigantamax, appear. Dynamaxing allows for Pokémon to grow to great sizes and battle other giant Pokémon. Their moves also get Dynamaxed and have new attributes. Gigantamaxing is similar, but the Pokémon grows bigger and changes its appearance too.
Overworld roaming Pokémon return from Let's Go Pikachu and Eevee. Pokémon can also be found in random encounters within the grass. Overworld Pokémon also act differently from the previous game. Certain Pokémon wander around outside of grass; some Pokémon chase after the player, and some Pokémon will run or fly away from the player.
The Poké Ball Plus device can also work for these games. However, it won't function as a controller like it did in Let's Go Pikachu & Eevee.
The player can lure wild Pokémon from grass by whistling, as well as sneaking through grass to get close to the shy Pokémon that normally run away.
Overworld weather attributes reappear such as snow, rain, sun, and sandstorms. They can change what Pokémon appear. For instance, Wingull appear in the rain and Snover appear in the snow. Weather conditions can also stack. For instance, during thunderstorms, the effects of Electric Terrain and rain will both be present.
Bikes return after their absence in Sun & Moon and Ultra Sun & Ultra Moon. They can now speed up and can ride on water, unlike previous games.
Similarly to the Alolan forms in Sun and Moon, they have Regional variant in the Galar Region known as the Galarian forms. Galarian forms even has evolution of some of the Regional variant of Pokémon that is only exclusive to that type of Regional variant.
This is the second pair of Pokémon core series games whose region is based on Europe, the first being Pokémon X and Y (France).
Information on these mainline games was revealed on February 27, 2019, also known as Pokémon Day around the world, as it was the date that the first Pokémon games hit store shelves in 1996.
After five generations, the Poké Ball no longer serves as the handakuten in the Po (ポ) of "Poketto Monsutā" (ポケットモンスター) in the Japanese logos. Additionally, "Poketto Monsutā" is written in the style of the international logos of the franchise. The top stroke in the N (ン) is replaced with the Pokémon Gym logo, however.
These are the first main-line games to:
Release on a home console, as the Nintendo Switch is a hybrid of both home and handheld consoles.
Have a wide open-world sandbox area, similar to the PokéPark game series.
Have version-exclusive Gym Leaders that use different types.
The Pokémon Company and Uniqlo once held a collaborative T-shirt design contest in May 2019 to select the designs of the champions as the player characters' outfits. Unfortunately, since both the champion and another contestant's designs had violated the contest rules, Uniqlo ultimately halted this project with the Pokémon Company.