Playing in another language

Sorry I seem to remember seeing an answer to this question before, but I can't find it now.

What's the site policy on playing a game here in another language? I'm getting some people together to play a game in Esperanto.

I don't have a policy in place, but I don't see why I should object. As long as it follows all the rules, I don't mind. As it's a language I don't know (and we don't have any other site admins right now), I will be harsher if I find rules being broken.