Cognitively demanding electoral systems increase the chance that voters make their choices based on politically irrelevant cues. To illustrate this argument, I analyze the effect of candidate name complexity—a visual cue that contains no politically meaningful information—in Japan, where voters need to write their preferred candidate's name on a blank ballot paper. I find that when electoral systems require voters to weigh a large number of candidates and simultaneously reduce the usefulness of partisan cues, candidates with more complex names tend to receive lower vote shares. By contrast, under less cognitively demanding systems, candidate name complexity has no effect on election outcomes. These findings have important implications for the debate on the “best” electoral system design.