Nintendo’s Palworld Fight Over Pokemon Patents Just Got Uglier: US IP Expert Calls Mods Defense a Desperate Hail Mary
Under mounting scrutiny, a key figure draws a hard line—"I would never make that argument in a million years"—a defiant rebuke that raises the stakes in an escalating fight.
Here is the short version: Nintendo says game mods don’t count as prior art. A US patent lawyer says that take is nonsense. And yes, this is all part of the long-running Palworld lawsuit.
Quick recap
Nintendo and The Pokemon Company have been suing Palworld developer Pocketpair for over a year, accusing the survival game of stepping on multiple patents. The big ones allegedly cover Poke Ball-style catching and how you mount, board, and ride creatures. Pocketpair’s defense? Point to prior art — proof that these ideas existed before Nintendo filed the patents — including a Dark Souls 3 mod called Pocket Souls, a Pokemon-like tweak built on FromSoftware’s 2016 action RPG.
Nintendo’s argument
Nintendo pushed back and said mods shouldn’t count as prior art because they can’t exist on their own without the base game. If that sounds very specific and very technical, that’s the point.
The expert pushback
Patent attorney Kirk Sigmon — a partner at Banner Witcoff who litigates and prosecutes IP cases — is not buying Nintendo’s stance. In a video chat with Grokludo, he went straight at it:
"Nintendo is so wrong, it hurts."
He says he doesn’t know why Nintendo made that argument and suspects there may be some nuance in Japanese law behind it. But speaking broadly about patent law, especially in the US, he says prior art doesn’t need to be perfect, polished, or even functional software.
Inside baseball: what actually counts as prior art
Sigmon points to a real example from an inter partes review — basically a proceeding to re-check whether a patent should have existed in the first place — where a Dungeons & Dragons manual counted as prior art. Not a video game, just a book describing character sheets and systems relevant to the patent being challenged. The key is whether the reference existed and can be dated, not whether it was shipped, marketed, or standalone.
- Prior art doesn’t have to be functional software; it can be documentation.
- It doesn’t have to be sold or marketed — it just has to be publicly available in some form you can timestamp.
- Mods can qualify if they show the relevant functionality, even if they ride on a base game.
- Courts and the patent office have even used references that were never built and had obvious flaws.
- There may be quirks in Japanese law, but in the US, Sigmon calls Nintendo’s position a loser argument.
His bigger point: if you start excluding things just because they run on something else, where does that stop? By that logic, are Unreal Engine 5 games 'mods' because they rely on the engine? It becomes a definitions spiral where, in his words, no one knows what the hell is going on.
The subtext, according to Sigmon
Sigmon doesn’t mince words. He thinks Nintendo is throwing a Hail Mary because there is a lot of potentially invalidating material out there. He even speculates that deep down Nintendo knows some of these patents are weak and doesn’t want an official invalidation on the books. He would never make the 'mods don’t count' argument himself.
Where this leaves the case
The lawsuit is still alive, so none of this is the final word. But if Sigmon is right, Nintendo’s attempt to carve mods out of prior art may not hold up, at least under US standards. The Japanese-law angle could get complicated, but that’s the only lane where he sees any wiggle room.
Meanwhile, in the discourse
Separate but related drama: a veteran from Resident Evil and Street Fighter took heat after telling people 'please don’t buy' Palworld, saying Pocketpair 'crossed a line that should not be crossed' — and then admitting he hasn’t actually played the game. So, productive conversation all around.