One big difference between the games is which Pokémon you'll encounter. For the most part, it's the same lineup, but there are a handful of big version exclusives in Pokémon Sun and Moon. Read on for a full breakdown that should make your decision a little easier.
Pokémon Sun and Moon version exclusives: Alola forms and legendaries
The biggest Pokémon Sun and Moon version exclusives aren't much of a surprise. Depending on which game you pick you'll be able to capture just one of the two main legendary Pokémon introduced this year.
For Pokémon Sun that means Solgaleo, a majestic psychic/steel-type lion with a special move called Full Metal Body to protect it against enemy attacks. Meanwhile, Pokémon Moon players can catch Lunala, a beautiful flying psychic/ghost-type with a special defensive Shadow Shield ability.
Pokémon Sun and Moon also introduces Alola form versions of classic pocket monsters. Some will be available in both games, but a few are version exclusives. Specifically, Sun players can catch the Alola forms of Vulpix and Ninetails, while Moon players get Sandshrew and Sandslash.
Pokémon Sun and Moon version exclusives: Rockruff evolutions
Here's another interesting difference. Rockruff, a new dog-like Pokémon introduced in Sun and Moon, will evolve differently depending on which game you play.
Rockruff always evolves into Lycanroc, but which version of Lycanroc you get will vary. In Pokémon Sun you get the normal-looking daytime Forme. However, Pokémon Moon offers up a wilder looking nighttime Forme of the Pokémon.
Pokémon Sun and Moon version exclusives: Even more differences
Still not sure which game to pick? Maybe these Pokémon Sun and Moon version exclusives will help.
In Pokémon Sun you can catch Passimian, a fighting-type monkey Pokémon, along with Tortunator, a fire/dragon-type Pokémon that lives on volcanoes. Alternatively, Pokémon Moon includes Oranguru, a normal/psychic-type monkey Pokémon, along with Drampa, a normal/dragon-type that's found high up in the mountains
Pokémon Sun and Moon version exclusives: Ultra Beasts
Finally, there's the Ultra Beasts, mysterious new Pokémon from beyond Earth. You'll meet multiple Ultra Beasts in Pokémon Sun and Moon, but there are a few differences between the two games.
In Pokémon Sun you'll encounter UB-02 Absorption (also called Expansion), which looks like a big red muscular mosquito. Alternatively, Pokémon Moon includes UB-02 Beauty, which looks like a slimmer bug that could focus on speed instead of strength.
Pokémon Sun and Moon version exclusives: How to catch 'em all
If you're determined to catch 'em all don't worry, you won't need to buy both Sun and Moon just to round up all the new Pokémon. Just find someone with the other version of the game to trade with so you can complete your collection.