The show focuses on Blaze, a red monster truck, and his smart young driver, AJ. They live in a world that involves many living monster trucks called "Monster Machines". Their friends include their truck friends, Starla, Stripes, Zeg, Darington, and Watts (as of Season 3), as well as a girl named Gabby, who is a mechanic who can fix anything and later on Watts' Monster Machine driver and close friend (as of Season 3). Each episode also features Crusher, a sneaky blue truck who cheats in races. Crusher is always accompanied by a small truck named Pickle, his goofy sidekick.
Each episode has Blaze and AJ go on various adventures and solve problems along the way, normally three per episode, with "assistance" from the viewing audience. Blaze might also transform into a different vehicle or artifact depending on the situation. Blaze may sometimes get a task done with the help of his Blazing Speed, a special power that allows him to go super fast.
Animals in this monster machine world have blended windows (which have been removed as of Season 5) and wheels; however AJ and Gabby are humans. In some episodes, Blaze, AJ and their friends are in a race against Crusher. During the race, Crusher cheats, usually with the help of his gray robot parts. However, Blaze and AJ manage to get through his traps, and they always beat him in time.
Some episodes do not involve races, but still have Blaze competing against Crusher, sometimes by racing against him to get an item. Other episodes involve helping a truck friend such as Starla, Zeg, Darington, Stripes, Watts, or even Crusher and/or Pickle.
