A biased link occupation rule discourages the growth of large clusters much ahead of others and encourages faster growth of clusters which lag behind. The resulting percolation transition, proposed recently, is discontinuous, and referred to as 'Explosive percolation'. We will discuss the results on a variety of graphs. We also introduce a new model with a single parameter alpha, and show that the transition is discontinuous for alpha < alpha_c and continuous above. Our model might help in understanding the mechanism for this novel transition.