Despite speaking in multitude of languages, participants in the conversations clearly understand each other, or everyone speaks some universal language that just happens to be English or equivalent.
Alternate names: Universal translator, Universal tongue
The first video game about Universal language was released on November 1992.
Sci-Fi instances tend to have universal translators, but even they occasionally fail at it. Such as Star Trek where plenty of people speak with differing languages (Wookiees with their howls being a very obvious example) yet understand each other perfectly. Somehow everyone conveniently understands the "universal" language used by the protagonists and they understand everything spoken to them by others.
In fantasy settings this is so common it's probably hardly worth noting. Though references to their language is clear sign of universal language at work.