They have applied for and received Patents in the US recently that pertain to their case against pocketpair

Nintendo obtained yet another just last week, it seems, as reported by Games Fray – and one yesterday. The new US patents include one related to a "smooth switching of riding objects" mechanism, and another that's far more concerning, as it could change the way that non-Pokemon creature collectors work forever: a patent covering the summoning of a "character" (in Palworld's case, that would be a Pal) and using it in combat against others.<

• https://www.gamesradar.com/games/survival/as-the-palworld-lawsuit-rumbles-on-nintendo-claims-two-new-patents-that-could-change-the-way-non-pokemon-creature-collectors-work-for-good/

True, thanks. WIPO has made sure differences between national patent laws, if any, are minor.

What the Law requires for an inventive step?

a patent shall not be granted for an invention where a person ordinarily skilled in the art could have been easily make the invention based on the prior art at the time of filing. Thus, the law requires that a patentable invention should involve such an inventive step that the skilled person could not have made the invention based on the prior art at the time of filing.

https://www.jpaa.or.jp/en/ip-information/patent-others/