  There are several different game description languages (GDLs), each intended
to allow wide ranges of arbitrary games (i.e., general games) to be described
in a single higher-level language than general-purpose programming languages.
Games described in such formats can subsequently be presented as challenges for
automated general game playing agents, which are expected to be capable of
playing any arbitrary game described in such a language without prior knowledge
about the games to be played. The language used by the Ludii general game
system was previously shown to be capable of representing equivalent games for
any arbitrary, finite, deterministic, fully observable extensive-form game. In
this paper, we prove its universality by extending this to include finite
non-deterministic and imperfect-information games.
