This article examines discrimination based on hukou status, a legal construct that segregates locals and migrants in urban China. Local and migrant household helpers were recruited as experimental participants to interact in a standard gift exchange game (GEG) as well as a new variant of the GEG, called the wage promising game (WPG). The WPG uses non-binding wage offers and final wages that employers set after observing effort. In the GEG, both statistical and preference-based discrimination may motivate employers to offer lower wages to migrants than to locals, whereas in the WPG the statistical motive is excluded. Results reveal discrimination against migrants and show that preference-based discrimination is an important employer motive.