The Challenge Belt (sometimes referred to as the WAR Challenge Belt) was a winner stays on competition held in both series of Robot Wars Extreme, as well as in Nickelodeon Robot Wars. The rules were that anyone could challenge the holder for the belt and if they declined, they lost by default. Three successful defences and they would keep the belt and be given another one to defend.
- Main article: Robot Wars Extreme: Series 1/Challenge Belt
At the start of Extreme 1, the belt was awarded to Behemoth by the fictional 'World Association of Robotics' or 'WAR' because of the teams' claim that it was unbeatable and the first challenge was the main event of the first episode. Behemoth defeated Stinger and The Steel Avenger before losing to Tornado. Tornado went on to defeat Comengetorix and Wild Thing to take the first belt and was awarded another one to defend. It beat Chaos 2 and Pussycat, but no third challenge came.
- Main article: Robot Wars Extreme: Series 2/Challenge Belt
The format of the Challenge Belt changed drastically for Extreme 2, because Tornado needed a third challenge. It was now a knockout tournament between eight robots, the winner of which would get to give Tornado its third challenge. Terrorhurtz defeated Dantomkia to win the knockout competition, only to be defeated by Tornado in under 20 seconds, the shortest battle in Extreme 2.
- Main article: Nickelodeon Robot Wars/Challenge Belt
The rules were the same as in Extreme 1 and the Challenge Belt was awarded to Tyranabot for winning the US Championship. However, it lost to Tut Tut in the first challenge, who beat Rosie the Riveter 2 and Probophobia to win the belt. However, due to time restraints, Tut Tut was not given another belt.