Taikyoku Shogi
Until today I’d only heard of the most popular variant of shogi, often called Japanese chess, featuring a 9x9 board but with a broadly similar rule-set. I was dimly aware that other versions existed, and that they had larger boards (chess also has plenty of variants with more than 64 squares) but today I learned about the mind-bending Taikyoku Shogi, clocking in at a much heftier 1296 squares, or a 36x36 board. How two people could ever hope to remember the rules for each individual piece, let alone have such a firm grasp on them that they could effectively coordinate and strategise using them is absolutely beyond me. The names of the pieces also absolutely put those of standard chess to shame.
As fun as it looks, the consensus does seem to be that it’s basically impossible to actually play. If I decide to learn any popular Asian board games, it looks like I’m going to be sticking with Go.