Still embarrassed about that time you left a tip at a pub abroad and were chased down the street by the management for "forgetting your money"? One helpful Reddit user has provided a handy map of tipping customs around the globe so you can be a more worldly diner.
The color-coded atlas reveals that tipping is expected basically only in the U.S., Canada, and a few rogue countries in South America/Africa/Europe. "In limited circumstances" is way more dominant, followed by "rounding of bill common", and then "uncommon". There's already an interesting debate about the whole thing unfolding on the Reddit thread, so hop on over there and educate yo'self.