Yes. Game Freak has moved on to Pokémon Sword/Shield and Scarlet/Violet. No further updates for Ultra Sun/Ultra Moon will ever be released.
However, the community has built upon v1.2 via ROM hacks. If you have the v1.2 CIA installed, you can now layer mods like:
These mods often require v1.2 as the base patch because they rely on the updated file structure of a/0/1/2 inside the RomFS.
In v1.0, during the climactic battle against Giovanni in Team Rocket’s Castle, the background music would occasionally desync, causing a screeching noise. v1.2 patches the audio sequencing. pokemon ultra sun update 12 3ds world cia
An update (v1.2) patches the game engine. DLC adds new content (e.g., the Mewnium Z or the Team Rocket outfit). You can install both—they do not conflict.
It would be irresponsible to write this guide without addressing the elephant in the room: Copyright.
Our advice: If you own a legitimate copy of Pokémon Ultra Sun (cartridge or digital), downloading the update CIA to preserve your ability to play on CFW is ethically justified. If you do not own the base game, you are pirating. These mods often require v1
Furthermore, installing random CIAs from the internet carries risk. Malicious actors have embedded brick code (though rare) or spyware that phones home to Discord webhooks. Always check the file hash against a trusted database (like No-Intro or the Internet Archive’s Redump collection).
Prerequisites: You must have a hacked 3DS (Custom Firmware). This process does not work on a stock, unmodified console.
For players using a "New 3DS" (with the C-stick), v1.2 stabilizes the frame rate from a fluctuating 20–30fps to a locked 30fps inside the wormhole tunnel. On an original 3DS, this prevents motion sickness. It would be irresponsible to write this guide
When Nintendo released Pokémon Ultra Sun and Ultra Moon in November 2017, the cartridges shipped with version 1.0. As with most modern games, post-launch patches were required to fix server-side issues and glitches.
Update Version 1.2 (sometimes listed as v1.2) was the final major patch released for the game suite. Unlike v1.1 (which primarily fixed text errors and a softlock in the photo club), v1.2 addressed core functionality:
For players using a physical cartridge or an official eShop download, this update is downloaded directly from Nintendo’s servers. However, for users who have installed a CIA (CTR Importable Archive) of the base game—often to play a "World" version (USA/EUR region-free)—you need the corresponding update CIA.