Before you hunt for the files, let’s look at why this specific title is worth the storage space on your SD card or HDD.
| Format | Type | Installation Required | Update Compatible | Use Case | |--------|------|----------------------|-------------------|-----------| | XCI | Cartridge dump | No (mount via CFW) | Yes (via layered FS) | Physical backup, emulation | | NSP | eShop dump | Yes | Yes | Digital backup, emulation | | UPD | Patch file | Yes (over base) | N/A | Bug fixes, performance |
If you are playing a legitimate copy, the update (v1.0.2) fixes several issues:
From a technical backup perspective, a scene release labeled “Base + UPD v1.0.2” means the packager has already merged the update into the base game, making it a “ready-to-play” XCI or NSP.
Pokémon: Let’s Go, Pikachu! (and Eevee!) are 2018 Nintendo Switch remakes of Pokémon Yellow, blending:
It runs on a heavily modified version of the Pokémon Sun/Moon engine, not Sword/Shield’s engine.
For the average player, the discussion around NSP, XCI, and UPD is irrelevant—just buy the game from the eShop or a physical retailer. For preservationists, modders, or those running custom firmware, understanding these formats is essential to properly managing Pokémon: Let’s Go, Pikachu!.
As always, support the developers. The Let’s Go series remains a charming entry point for casual fans, and its technical simplicity makes it a favorite for both legitimate players and those exploring Switch software architecture.
Disclaimer: This article is for educational purposes regarding file formats and system architecture. The author does not condone piracy. pokemon lets go pikachu switch nsp xci upd upd
The fluorescent lights of the electronics shop buzzed overhead, a familiar drone to anyone hunting for retro deals. But Elias wasn’t looking for cartridges with peeling labels today. He was on the hunt for something more elusive: the digital ghost.
He sat in the corner of a cramped coffee shop, his Nintendo Switch docked to a small portable monitor. His friend, Mia, sipped a latte and watched him scroll through a custom home menu.
"Remind me why you're doing this again?" Mia asked. "You own the physical cartridge. You beat the Elite Four three times. Why are you messing with... what is that? XCI? NSP?"
"It's about the 'UPD'," Elias muttered, his eyes glued to the screen. "The Update file. Look, when Pokémon: Let’s Go, Pikachu! launched, it was a bridge between the mobile craze and the mainline series. But the version on the card is version 1.0. The world moved on. The game got patches. Secret little fixes."
Elias was a digital archivist of sorts. He wasn't just playing; he was preserving. He had acquired the NSP format—a digital dump of the eShop version—and the XCI—a dump of the cartridge. But the file he was currently installing was the mysterious upd file.
"Most people just update their games naturally," Elias explained, tapping the screen. "But in the emulation and preservation scene, the 'UPD' file is the bridge. It takes the base game and injects the official Nintendo patches that are no longer accessible on the official servers for modded consoles."
He initiated the installation. A progress bar crawled across the screen. Installing content...
"Sometimes," Elias whispered, leaning in, "these updates change spawn rates. They tweak the physics of the Poké Ball throwing mechanics. I heard a rumor that version 1.0.2 changed the way Partner Pikachu's tail wagged during the starter selection screen. It's tiny, trivial details that get lost to time if we don't archive the UPD files." Before you hunt for the files, let’s look
The bar hit 100%. The screen flickered.
"Okay, it's done," Mia said, unimpressed. "It's just Let's Go. It's Kanto. We've seen Kanto a million times."
Elias launched the game. The opening cinematic played, but something felt different. The colors were slightly more vibrant. The startup sequence was smoother.
"See," Elias said, pointing to the bottom right corner of the title screen. "Version 1.0.2. Most physical copies are still sitting on 1.0. Without that NSP update file, you're playing the game as it was on launch day, bugs and all."
He loaded his save file. He was in Viridian Forest. In the base version 1.0, the frame rate could chug when too many Pokémon spawned on screen. But now, with the update injected, the Butterfree fluttered past in silky smooth motion.
"Look at the shadows under the trees," Elias said, his voice filled with the reverence usually reserved for fine art. "In the unpatched XCI, the shadows were blocky static textures. The update optimized the engine. It’s a better experience. A definitive version."
Mia finally cracked a smile. "So, you went through all that trouble of finding the NSP and the update file just to fix the shadows?"
"Not just that," Elias said, grinning. "Version 1.0 had a glitch where the motion controls for catching Pokémon were slightly desynced if you played in handheld mode too long. The UPD fixed it. It turned a gimmick into a polished mechanic." From a technical backup perspective, a scene release
He threw a Poké Ball at a random Pidgey. The motion was responsive, crisp. The ball clicked shut.
"I guess that's the beauty of it," Mia admitted. "Most people just play. You guys make sure the play stays perfect, even when the servers go dark."
"Exactly," Elias said, saving his game and powering down the monitor. "An XCI is a snapshot of the past. The NSP is the digital present. But the UPD? That’s the history lesson in between."
Here’s a deep write-up on Pokémon: Let’s Go, Pikachu! for Nintendo Switch, focusing specifically on the NSP / XCI formats, updates (UPD), and DLC — aimed at users familiar with switch modding, but also explaining the technical and gameplay context.
💡 Update must match same region and base game – otherwise fails “corrupt data” error.
Assuming you have legally dumped your own game or are using files for a console you own, here is how to handle the “upd upd” portion of the search.
Like most modern games, Pokémon: Let’s Go, Pikachu! received several post-launch patches. These are distributed as UPD files (or simply “update NSPs”). The key updates include:
Updates are cumulative. If you find a “UPD” for version 1.0.2, you do not need to install 1.0.1 first. The update file size is usually between 100 MB and 300 MB, depending on the version.
Important: To apply an update, the base game (either XCI or NSP) must already be present. Updates can be installed over an XCI as well, though some CFW setups require converting the XCI to installed NSP for seamless updates.