[SLSMan]

(Patent attorney) The patents in question are continuation patents. Essentially, Nintendo filed a patent application before Palworld was released that disclosed the mechanics Nintendo is patenting now. That original application only included claims covering a subset of the mechanics described in the application. They can continue filing additional applications with new claims that cover the mechanics described entirely in the original application and get the benefit of having the priority date of the original application so long as they meet certain requirements about the timing.

Original application: I invented A, B, C, D, E, and F and want A protected; here’s some $. Follow-up application 1: I want invention B protected, here’s some more $. Follow up application 2: I want C protected, here’s some more $.

Part of the idea behind it is that you don’t have to waste money protecting parts of what you invented that don’t pan out (additional claims cost additional money beyond a certain number of claims). It’s not particularly fair, since you can watch what a competitor does (as Nintendo has done here), and essentially backdate a patent as though you had filed for it before the competitor did their thing.