This research was about designing English game based on role play technique to improve students’ speaking skill at tenth grade of SMA N 1 Tahunan in the academic year of 2021/2022. The aim of this research was to design an English game based on role play technique for tenth grade students at SMA N 1 Tahunan Jepara. The game designed was intended to help students practice speaking in order to develop their speaking skills. This research was a research and development using the design of Borg and Gall, Samsudi, Sugiyono. The population of this research is the X grade students of SMA N 1 Tahunan, totaling 216 students. The sample of the research was X MIPA 6 as the experimental group and X MIPA 5 as control group, that every group consisted of 38 students. The sample was taken by using random sampling technique. There were two variables in this research, they were designing English game based on role play technique as the independent variable and students’ speaking skill as the dependent variable. The instrument of this research was oral test. The result of the test’s data indicated that there was a significant difference between both classes, the mean score of pre-test in experimental group was 71,44 and the mean score of pre-test in control group was 73,89. Meanwhile, the mean post-test score in experimental group was 82 ad the mean post-test score in control group was 75,67. It meant that English game based on role play technique was successful in developing students’ speaking skill. From the calculation of independent sample t-test in post-test, the result showed that the value of ttest > ttable (4,346 > 2,000). Because the value of ttest > ttable indicated that the alternative hypothesis (Ha) is accepted and the null hypothesis (H0) is rejected. Based on the findings and the discussion of the research, the researcher got a conclusion that English game based on role play technique was effective to improve students’ speaking skill at tenth grade of SMA N 1 Tahunan in the academic year of 2021/2022.