Should the game go be capitalized? The normal rule is that you only capitalize proper names or product names, but if I use the lowercase, it looks like a typo, with only the context reinforcing the name. Since the game is easily several hundred years old, there's no trademark remaining (it predates the use of trademarks).
Checking for uses online, I found the Brit Go Association webpage, which does capitalize the game, both in title cases and common (mis-sentence) uses.
Since everyone here argues over context, here's an unambiguous example from my story:
Instead of responding, Em turned to her partner. "You play chess? I'd think you'd be a go aficionado."