For a graph G = (V;E) with V = V (G) and E = E(G), a Roman f3g-
dominating function is a function f : V ! f0; 1; 2; 3g having the property
that Pu2NG(v) f(u) 3 if f(v) = 0, and
Pu2NG(v) f(u) 2 if f(v) = 1
for every vertex v 2 G. The weight of a Roman f3g-dominating function
f is the sum f(V ) =
P
v2V (G) f(v) and the minimum weight of a Roman
f3g-dominating function on G is the Roman f3g-domination number of G,
denoted by fR3g(G). We initiate the study of Roman f3g-domination and
show its relationship to other parameters of Roman domination and double
Roman domination.