Abstract: A transformation construction system includes a toy figure set having a plurality of interconnectible building elements that are configured to connect to building elements of a construction set. The toy figure set includes a torso building element and a pelvis building element that interconnect with each other with an interference fit between a stud of the pelvis building element and a recess of the torso building element. A construction explanation identifies a first design mode that includes the toy figure set, a second design mode that includes the toy figure set and is distinct from the first design mode, and a set of instructions that show a transformation between the first design mode and the second design mode without disassembling the toy figure set and the plurality of building elements.