 An effectivity function is called playable (Pauly 2001) if it has liveness, safety, N-maximality and superadditivity. It is called truly playable (Goranko, Jamroga, &amp; Turrini 2013) if it is playable and well-founded. Observe that if \(W\) is finite, an effectivity function is playable if and only if it is truly playable (Goranko et al. 2013).