Content analysis of a large-scale (N = 920) qualitative data set with MAXQDA12 from a nationwide questionnaire of nursery practitioners in Hungary was able to demonstrate various types of rules during free play: social, health and safety, and environment-related rules. Environment-related rules, which govern space utilisation in toddler groups, have not been previously described in the literature but seem to be part of the practical know-how of the profession. Whereas there was a general agreement among respondents for social and health and safety rules, some disagreements in the presentation of environment-related rules were detected. Responses of a subsample (N = 255) consisting of three groups (N = 85) were analysed quantitatively: frequencies of environmental-rule-contents were statistically compared between a trainee group and two matched (a colleague and an independent) experienced nursery nurses' groups (chi-squared test, one-way ANOVA). For trainee nursery practitioners, rules have a greater importance (p < 0.05) than for experienced caregivers.