3D Construction Kit (US, Canada & Israel release title: Virtual Reality Studio[3]), also known as 3D Virtual Studio, is a utility for creating 3D worlds in Freescape. Developed by Incentive Software and published by Domark, it was released in 1991 on multiple platforms. A sequel, 3D Construction Kit II, was released in 1992.

The kit has a very simple graphical user interface, allowing users to create and manipulate objects within the game's 3D environment. Primitives such as cubes, cuboids and pyramids can be easily created and edited to be scaled and placed on the 3D world. Colours can be selected for individual elements, making the free roaming worlds more varied and complex. The user-created virtual world is divided into areas, reducing the processing power required to render objects. The areas can be as large as the memory allows.

In order to make games rather than worlds, 3D Construction Kit also allows for the addition of conditions, using the very simple-to-program Freescape Command Language (FCL). Sensors, animations and interactivity with the elements can be added with relative ease. Players are able to move around the virtual worlds by walking or flying. Elements such as proximity sensors triggering events, enemies making the player appear in another zone of the game when hit, and the ability to activate switches in order to open doors, make the worlds created with 3D Construction Kit come to life and add a level of uncertainty to the gameplay.