a b s t r a c tA subset D ⊆ V of a graph G = (V , E) is a (1, j)-set (Chellali et al., 2013) if every vertex v ∈ V \D is adjacent to at least 1 but not more than j vertices in D. The cardinality of a minimum (1, j)-set of G, denoted as γ (1,j) (G), is called the (1, j)-domination number of G. In this paper, using probabilistic methods, we obtain an upper bound on γ (1,j) (G) for j ≥ O(log ∆), where ∆ is the maximum degree of the graph. The proof of this upper bound yields a randomized linear time algorithm. We show that the associated decision problem is NP-complete for choral graphs but, answering a question of Chellali et al., provide a linear-time algorithm for trees for a fixed j. Apart from this, we design a polynomial time algorithm for finding γ (1,j) (G) for a fixed j in a split graph, and show that (1, j)-set problem is fixed parameter tractable in bounded genus graphs and bounded treewidth graphs.