Comment by LinuxBender

I assume the existing captcha services look at the Accept-Language header. That header could be read by the Lua script. Each puzzle set could be translated one time through google translate or perhaps a better translation site. It should probably be proof read by someone from each language used to ensure nothing translates out of context into something offensive. I think I've seen people do this on Github, having people proof read translations. In this case it probably should be a smaller group to reduce risk of leaking the puzzle mapping to the bot code authors.