The null‐collision concept is introduced into the direct‐simulation Monte Carlo method in the rarefied gas dynamics. The null‐collision technique overcomes the principle fault in the time‐counter technique and the difficulties in the collision‐frequency technique. The computation time required for the null‐collision technique is comparable to that for the time‐counter technique. Therefore, it is concluded that the null‐collision technique is superior to any other existing techniques in the direct‐simulation Monte Carlo method.