The Curriculum and Assessment Policy Statement (CAPS) reforms in the South African school system came with an increased emphasis on laboratory practicals for the physical sciences. While reform implementation is known to be fraught with a myriad of challenges, for science teachers such significant changes in the practical components magnified the complex nature of the process. This article reports on physical sciences teachers' perceptions and experiences regarding the prescribed laboratory practicals. We use complex theory to unpack teachers' perceptions and their planning (or not) for the implementation of these prescribed practical components. In this qualitative study, we conducted document analyses on curriculum documents and the laboratory instruction activities, and semi-structured interviews with three teachers from different schools. All participants perceived the prescription of the laboratory experiments positively. The prescription of the experimental practical activities is on two levels: firstly, a list of experiments for each grade provided by the national Department of Basic Education (DBE), and secondly, authorities at the provincial level provided detailed write-ups that serve as lesson plans for the practicals. The provided practical laboratory write-ups offered limited opportunities for good laboratory instruction such as inquiry-based learning.