How do political parties attack each other in multi-party systems? While voters in multi-party systems respond to attacks on the honesty, integrity, and competence of political actors, it is unclear whether and how political parties use these valence attacks strategically. I argue that valence attacks are more likely to occur in multi-party systems when they appear legitimate to voters. I connect the vast literature on spatial competition with the one on valence attacks and argue that incumbency and issue ownership increase the public perception of legitimacy and make attacks more likely. Using data from 18 recent elections in ten European countries, I show that valence attacks in multi-party systems focus on incumbents and are predominantly connected to substantive issues. These findings have important implications for the literature on valence attacks by parties as well as the one on strategic position taking in electoral competition.