On a daily basis, children make decisions about how to negotiate their physical environment. Sometimes they engage in physical tasks that involve risk, requiring them to judge the safety of how to negotiate the environment safely. Individual differences in children's age, sex, physical size, and personality may impact those decisions. We used fully immersive virtual reality to assess 7-10-year-olds' (n = 393; mean age = 8.8 years, SD = 0.8; 50% female) behaviour while stepping across rocks to cross a simulated river. Children's self-reported thrill and intensity seeking (TIS) personality was also collected. Three outcomes were considered: rocks stepped on, time evaluating the crossing, and time crossing. On average, children used 5 of 7 rocks, spent 7.8 s assessing, and 18.7 s crossing, with substantial individual variations. Taller children crossed using fewer rocks, but this association was subsumed in multivariable models by male gender and higher TIS personality (e.g., [beta] = -5.2 and -2.6, respectively, predicting crossing time). Results have implications for child development theory, injury prevention, playground design, and parenting decisions.