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Advancements in materials research have led to a relatively new alloying technique coined high entropy alloys, which utilize a combination of at least five metals in approximately equiatomic proportion that contribute to a high entropy of mixing. Throughout the past two decades, in-depth research has been performed on the various characteristics of these alloys, as they have been found to possess admirable properties, such as high yield and creep strength, corrosion and oxidation resistance. Alloys usually contain lattice defects such as dislocations, voids, and precipitates. A fundamental material property, strength, can be largely understood by the interactions between these defects. Here, using atomistic simulations, the interactions between dislocations and voids are studied in a series of CrMoxNbTaVW1-x refractory high entropy alloys with x varying from 0 to 1, in increments of 0.2. Focus is placed on two critical stresses: one that is required for the dislocation to bypass the void and the other that is required for the dislocation to glide in a void-free lattice. The strengthening effect of voids, represented as the ratio between the two critical stresses, is discussed. Results are compared with those in pure metals.