Given a family scriptF and a host graph H, a graph G⊆H is scriptF‐saturated relative to H if no subgraph of G lies in scriptF but adding any edge from E(H)−E(G) to G creates such a subgraph. In the scriptF‐saturation game on H, players Max and Min alternately add edges of H to G, avoiding subgraphs in scriptF, until G becomes scriptF‐saturated relative to H. They aim to maximize or minimize the length of the game, respectively; sat gfalse(scriptF;Hfalse) denotes the length under optimal play (when Max starts).
Let scriptO denote the family of odd cycles and Tn the family of n‐vertex trees, and write F for scriptF when F={F}. Our results include sat gfalse(scriptO;Knfalse)=⌊n2⌋false⌈n2false⌉, sat gfalse(Tn;Knfalse)=false(0ptn−22false)+1 for n≥6, sat gfalse(K1,3;Knfalse)=2⌊n2⌋ for n≥8, and sat gfalse(P4;Knfalse)∈{⌊4n5⌋,⌈4n5⌉} for n≥5. We also determine sat gfalse(P4;Km,nfalse); with m≥n, it is n when n is even, m when n is odd and m is even, and m+⌊n/2⌋ when mn is odd. Finally, we prove the lower bound sat gfalse(C4;Kn,nfalse)≥121n13/12−Ofalse(n35/36false). The results are very similar when Min plays first, except for the P4‐saturation game on Km,n.