  In normal version of combinatorial game theory, all games are invertible,
whereas only the empty game is invertible in mis\`ere version. For this reason,
several restricted universes were earlier considered for their study, in which
more games are invertible. We here study combinatorial games in mis\`ere
version, in particular universes where no player would like to pass their turn
In these universes, we prove that having one extra condition makes all games
become invertible. We then focus our attention on a specific quotient, called
Q_Z, and show that all sums of universes whose quotient is Q_Z also have Q_Z as
their quotient.
