The study looked into development of the positional action in a natural theatrical action attractive to children instead of an artificial experimental procedure modeling a transition from the role to the position. The authors describe stages of a child's positional action, the process of creating an inner picture of a stage action, demonstrating that positionality of a stage action correlates with the child's preparedness for school and the level of solving cognitive decentration problems. It has been established that a children's puppet theatre is an effective means of developing arbitrariness in children.