One of the functions of playing video games is place for entertainment, but there are also people become stress while playing video games because of frustration (fail to achieve objective in video games). One of video games genre that nowadays is popular is Multi Player Online Battle Arena (MOBA). This MOBA games have high complexity and more challenging for player, so this genre is suitable for this research to see what in game events that makes player's stress. This research objective is to evaluate stress when playing video games using cognitive ergonomic approach to see what in-game characteristic that increase stress. Methods for this research are frequency analysis from average power, asymmetry, and alpha/beta ratio also theta/beta ratio. Frequency Analysis is conducted by using electroencephalogram data from respondent while playing DOTA 2. Based on result of this research, there are some conditions that affect and did not affect to player's stress to both experienced and first time player.