This paper employs the notion of a "career script" as a conceptual basis to examine how age-based academic career norms are internalized, strategized, and reproduced among PhD students aspiring to become academics. It draws on interviews with 70 PhD students at leading universities in mainland China, Hong Kong, and Macau that were organized and explored using narrative inquiry. The findings suggest that the tournament-like, age-based career scripts are primarily shaped by institutional policies on recruitment and funding applications and reinforced through social interactions. Doctoral students internalize the established criteria for success defined by the career scripts and stigmatize those who lag behind in the attainment of institutionally predetermined milestones, thus discouraging any attempt to rescript career norms. While enacting successful career scripts, students experience age and temporal anxiety at a fairly young age, exacerbating ageism in the academic labor market.