Comedian Rob Beckett is the guest judge as the Lego building show returns. The teams compete to construct a skyscraper and a metre-long bridge that will withstand a weighted dumper truck .
The 7 teams do battle in a drop test to see which model gets smashed up the best. They also build a memorable scene from history. Joining the judges is comedian Paddy McGuinness.
The teams compete to build a hybrid land and sea animal and a life-size crazy golf feature. Comedian Chris Ramsey tees off as today's celebrity guest judge.
It's the final and the remaining four teams build a walking-talking robo-pet. There is also a Master Build using as many as half a million bricks. But who will be crowned the winner for 2018?
Six young builders from previous shows team up with celebrities to do battle in a range of festive challenges in this Christmas Special of the build challenge.
