How Different Must It Be to Be a Different Game?

As you may have noticed, I have written in the past about the differences between the games Fae and Clans. I recently visited the page for Fae on Board Game Geek, and I noticed a forum discussion about why the game got a separate page from Clans. The short version is this: the admins at BGG originally felt that theme was irrelevant in determining what constitutes a separate game, but after outcry from fans (in large part because searching the database for games of a particular theme doesn't produce the desired results), they created a 'reimplements' function that links games with identical mechanics but differing themes.

This apparently resulted from the reworking of a game called Penguin, in which you stack coloured penguins into a pyramid, into a game called Game of Thrones: Westeros Intrigue, in which you play cards representing characters from one of four of the noble houses from that fictional setting into a pyramid arrangement. Mechanically, these are the same game. Although the construction and appearance of these games are markedly different, the rules governing what you do with them are identical.

As such, BGG gave them both the same listing. If you went to the page on BGG for GoT:WI, you'd see photos of both games jumbled together in the Images section, and a listing for 'Alternate Names' that included Penguin. But if you did a search for 'Antarctic Theme,' you'd get GoT:WI in the results, due to it being linked with Penguin.