One very amazing feature of the mainline Pokémon games is the enormous backwards compatibility with previous games in the series. Ultra Sun and Ultra Moon are part of the 7th generation of Pokémon games and it’s possible to import Pokémon from as far back as Red and Blue–the very first generation!
While you don’t need to import your old Pokémon to enjoy these games, eventually you’ll probably want to do so to help complete your Pokédex or whatnot. Or just so you can reunite with old friends. Still, with so many games out there, it can be difficult plotting a route between them, which is where we come in!
Unles explicitly stated, Pokémon Ultra Sun and Ultra Moon share the same compatibility rules as Pokémon Sun and Moon–since all of these games co-exist in the same 7th generation.
Pokémon Sun & Moon - 7th Generation
You can interact with Sun and Moon exactly as if they were Ultra Sun and Ultra Moon, via Quick Link, Festival Plaza, etc. However all Pokémon, forms, moves and items new to Ultra Sun and Ultra Moon cannot be traded or battled with.
As mentioned in the previous page, Pokémon Bank is your one-stop gateway to transferring and storing Pokémon between 7th generation games (Sun, Moon, Ultra Sun and Ultra Moon), as well as from 6th generation games (X, Y, Omega Ruby and Alpha Sapphire).
Pokémon X, Y, Omega Ruby & Alpha Sapphire - 6th Generation
Pokémon sitting in any of the 6th Generation games can be transferred to and from Pokémon Bank–and thus can be transferred to Ultra Sun and Ultra Moon. Easy as pie! You simply need to have Pokémon Bank present on the same 3DS (or 2DS) as your 6th generation game(s).
One Way Trip
Beware that Pokémon transferred to the next generation can never be sent back to the previous generation. This also holds true for the 7th generation and 6th generation games. Now, you may be slightly confused. Certainly, the 7th generation and 6th generation games can both directly access Pokémon Bank.
However, any Pokémon originating from a 7th generation game or that has been transferred to one will be highlighted in Pokémon Bank and can only be transferred to a 7th generation game. If you try to transfer it to a 6th generation game, you simply won’t be allowed.
Pokémon Gold & Silver (Virtual Console) - 2nd Generation
Pokémon from the second generation can be transferred to Ultra Sun and Ultra Moon, but only if they originate from the 3DS Virtual Console editions. Sorry, your Pokémon in your GameBoy cartridges are stuck forever. To do so, Pokémon Bank, Poké Transporter and the 2nd generation Virtual Console game must all be present on the same 3DS (or 2DS).
Pokémon Red, Blue & Yellow (Virtual Console) - 1st Generation
Likewise, you can transfer Pokémon from the very first generation to Ultra Sun and Ultra Moon if they come from the 3DS Virtual Console editions. Again, Pokémon Bank, Poké Transporter and the 1st generation Virtual Console game must all be present on the same 3DS (or 2DS).
From Old-school to New-school
Although Poké Transfer sends the 1st and 2nd generation Pokémon directly to Pokémon Bank, note that they can only be transferred to the 7th generation games, not any of the 6th generation games.
Pokémon Black, White, Black 2 & White 2 - 5th Generation
Pokémon caught in the Unova region can be transferred using Poké Transporter, just like the Pokémon from the 1st generation games. Similarly, you’ll need Pokémon Bank, Poké Transporter and the 5th generation game all present on the same 3DS (or 2DS).
Pokémon Diamond, Pearl, Platinum, HeartGold & Soul Silver - 4th Generation
This is where things get a bit more complex. Now you’ll need two DS or 3DS systems, one with a copy of a 4th generation game and the other with a copy of a 5th generation game. In the 5th generation game, you need to access the in-game PokéTransfer feature and transfer wirelessly.
Pokémon Ruby, Sapphire, Emerald, FireRed & LeafGreen - 3rd Generation
Finally we come to the end of the road. For this, you’ll need a DS. Insert a 3rd generation game into the GameBoy Advance cartridge slot and a 4th generation game into the DS card slot. In the 4th generation game, you can use the in-game Pal Park feature to transfer between the games.