This paper combines two ideas: (1) That the Lewisian best system analysis of lawhood (BSA) can cope with laws that have exceptions (cf. Braddon-Mitchell in Noûs 35(2):260-277, ; Schrenk in The metaphysics of ceteris paribus laws. Ontos, Frankfurt, ). (2) That a BSA can be executed not only on the mosaic of perfectly natural properties but also on any set of special science properties (cf., inter alia, Schrenk , Selected papers contributed to the sections of GAP.6, 6th international congress of the society for analytical philosophy. Mentis, Paderborn/Münster, ; Cohen and Callender in Philos Stud 145:1-34, , Erkenntnis 73:427-447, ). Bringing together (1) and (2) results in an analysis of special science ceteris paribus laws.