He's a shy, lazy Kansas teenager. He is ostracized by his family and only seems to get along well with his grandmother, Florence Norris. It is also with her that he will find a way to defeat the Martians: country music. Awarded by President Dale's daughter, it can be assumed that she also becomes his girlfriend.
Richie appears for the first time, watching the President's speech on television at his work in the coffee shop. Upon returning home, he shares his surprise about the Martians and learns that his brother Billy Glenn has volunteered to join the military. During goodbyes, Billy doesn't seem to care about Richie only telling him not to touch his things before pushing him and getting on the bus. Then he brings his grandmother to the nursing home and jokes with her even though she has amnesia and calls him Thomas.
Later, Richie is briefly seen watching the first conflict with the Martians in Nevada as well as the attack on Congress. As the film progresses, the Martians attack the entire planet, attacking various countries.
One evening, Richie is forced to flee the coffee shop destroyed by a Martian ship. While going in his parents' trailer, he must load a gun and defend the place with them. Growing worried, Richie sets off to find his grandmother while his parents are killed by a giant Martian robot. Pursued by this robot, Richie manages to sow him and crash him to the ground.
He then runs into the house where he finds Martians who have placed a machine just behind the head of his grandmother who unplugs her headphones. The music heard by the Martians causes them pain and causes their brains to explode, killing them. This is how Richie and Florence find a way to defeat them and go together to the radio station to broadcast the music all over the country.
When the Martians die, Richie and his grandmother are rewarded by Taffy with Honor medals. Richie then gives a short speech in which he says better people would have done more than him, thanks his grandmother for helping him save the whole world, and suggests people live in tipies. After which, Taffy asks him if he has a girlfriend which he doesn't. We can suggest that they are now together.