This study aimed to examine the effects of narcissism and identity on the perceptions of school violence. The participants were 300 high school students who read one of the scenarios that described a situation of clear school violence or a situation of ambiguous distinction between violence and prank, and answered the questions that measured their perceptions of school violence. The results showed a significant three-way interaction among narcissism, identity, and the clarity of school violence. Specifically, in the situation of ambiguous distinction between violence and prank, people with high levels of lack of identity and disturbed identity, which are negative aspects of identity development, were more tolerant of school violence as their narcissism increased. Using situations likely to occur in the school context, this study confirmed that identity, which is a major developmental task of adolescence, interacts with narcissism to influence the tolerance of school violence perceptions in the school context. Particularly, it is significant that we confirmed negative aspects of identity development, rather than positive ones, are more important factors in tolerant perceptions of school violence.