A data replacement apparatus according to one aspect of the present invention includes an acquisition unit, a determination unit, and a replacement unit. The acquisition unit acquires first control data having a value based on the position of a first device which can be mounted on a user's head and the position of a second device which can be gripped by a user. The determination unit determines whether or not a prescribed condition is satisfied. The replacement unit replaces the first control data with second control data when it is determined that the condition is satisfied. The second control data has a value not based on the position of the first device and/or the position of the second device.