The game follows the plot of the film closely and contains fragments from the film as cut-scenes. It starts with the player controlling the wizard Vitruvius as he attempts to defend his super weapon The Kragle against Lord Business and his robot minions. He is unsuccessful but tells Lord Business about the prophecy that one day the special one, a master builder, will stand up with the piece of resistance that holds the power to disarm The Kragle.
Entirely new is the introduction of two character types: master builders and regular builders. As the environments now consist entirely out of LEGO bricks, builders can manipulate them. Master builders such as Wildstyle are able to reshape the environment directly through a limited number of options, while regular builders like Emmet can access construction pages to create new objects through various pieces similar to how LEGO is built in the real world, often by selecting the correct pieces to progress.