The partial factor method is the most common approach to verify structural safety in Eurocode 7. Given the ongoing discussion on the European level to include also underground excavations in rock in the scope of the Eurocodes, there is a clear need to investigate the applicability of partial factors to the design of rock tunnels. However, implementing fixed partial factors, in accordance with the suggestion in the current Eurocode 7, may not be appropriate to account for the large uncertainties and variable conditions prevalent in rock engineering. This paper studies the critical characteristics and underlying assumptions of different reliability-based partial factor formats. The suitability of the analyzed partial factor formats to evaluate safety is analysed and discussed with reference to a design example of a rock-shotcrete interaction system for support against block failure in an underground opening. The results show that reliability-based partial factor methods outperform the traditional partial safety format suggested in the Eurocode in terms of accuracy and consistency.