In Australia, a professor is called to the microphone so he can make a speech. He starts with a silly joke but then he makes a nasty one, which leaves everyone in shock. A lady from the committee tries to make him stop, but instead the professor cuts one of her fingers off.
Everyone runs away in panic while the professor picks the finger with a napkin. Soon the police arrive and when the professor refuses to cooperate, he gets shot. With his dying breath, the professor tries to reach for his ringing phone to no avail.
In Louisiana, Elliot says goodbye to his pregnant girlfriend Shelby, who he’ll be marrying in a few days. Then he goes to work, only to learn that he’s getting fired for being too nice with the clients. These are terrible news to only because of the incoming wedding and baby, but also because Elliot needs his insurance to take care of his mentally challenged brother.
Afterward Elliot goes to check on his brother Michael, who is very scared to hear the news. Without insurance paying for outpatient care Michael will be sent back to a mental institution, which he doesn’t want because of how they treat him there. Next Elliot goes to visit his abusive father Samson to ask for help, only to discover that Samson has lost all his retirement funds and will now have to move with his son.
That night, Michael asks Elliot to drive him to the store so he can get his medicine. During the trip, Michael points out how weird it was that their father only became mean later after he magically started to make more money. After dropping Michael, Elliot stops at the traffic lights and gets annoyed by a fly circling around his face.
The traffic lights are strangely still on red when suddenly Elliot gets a call from an unknown number with a ringtone he didn’t choose. A mysterious voice calls him by his full name and announces that Elliot has been selected for a very unique game show that could make him tons of money. When Elliot tries to pass, the voice reveals it knows everything about him: his mom was killed in a car accident when he was nine, he has student loans, credit card debt, and trouble sleeping.
The voice even knows there’s a fly in the car and tells Elliot to swat it, promising to pay him one thousand bucks if he’s successful. Getting annoyed, Elliot quickly swats the fly, killing it. As soon as he does so, a message arrives to his phone saying the money has been deposited in his bank account.
Starting to worry, Elliot gets out of the car to check if someone is spying on him, but he doesn’t see anyone. At that moment the voice calls again and tells Elliot that his next challenge is to swallow the fly for exactly three thousand six hundred twenty-two dollars, which is what Shelby owes on her credit card. After the voice ends the call, the traffic light finally changes to green.
Minutes later, Elliot arrives home and checks his bank account online, confirming the money was deposited. Then Elliot takes out the fly and eats it, which causes the next prize money to instantly appear in his account. The voice calls again, saying that in just thirty-six hours Elliot can be very rich, he only has to complete eleven more challenges that will increase in value as he advances in the game.
If he makes it to the end, he’ll get six million dollars. If he fails any of the challenges, the game ends and Elliot loses all the money he made up to that point. There are rules to follow and the voice tells Elliot to be alone to hear them, so when Elliot sees Shelby leave her room, he starts moving around the house to avoid her, eventually hiding in the bathroom.
Telling anyone about the game, attempting to contact the organizers, or interfering with the game will also count as losing. Elliot presses one to accept the deal and the voice makes him sing “I will dance with the Golden Toad” to finish the registration. Then the voice says the next challenge will come tomorrow and hangs up.
Elliot goes back to Shelby and tells her he’s been organizing a surprise to get her off his back. The next day, Elliot goes to the park with Shelby and her parents but he can’t stop thinking about the call. As soon as his phone rings, he leaves the group and hears the next challenge: he must make a child cry in five minutes for five thousand dollars.
Elliot looks around the park and sees a little girl running, so he blocks her way and tells her that her parents are going to leave her in an orphanage. When she doesn’t believe him, he just points at the couple and says that’s why they’re talking about right now. The girl finally gets upset and cries as she runs back to the family and Elliot gets a message confirming the money.
Afterward he hurries to help his group pick up their things and gets in the car with Shelby, driving away as the girls’ parents run after him to throw a trash can at his car. Minutes later, the couple makes it to church to pick up Samson. While Shelby is stuck helping him get back on his wheelchair, Elliot gets a call with the new challenge: he must burn a nativity scene handcrafted by blind kids.
Shelby takes Samson to the bathroom and has to deal with all his complaints about the baby and their marriage, revealing he’s quite racist. That doesn’t stop him from asking her to help him with his zipper. Meanwhile Elliot uses this opening to steal the nativity scene and takes it to the backyard, where he lights it on fire and instantly receives the money.
However he fails to control the flames, which soon spread to the actual church. Elliot tries to put the fire out with the extinguisher, but it isn’t enough. Panicking, he runs to activate the alarm, then he finds Shelby and Samson to leave quickly.
Outside, he receives another call telling him that once he’s ready, he must follow the homeless person across the street. Elliot immediately leaves Shelby behind with his father, ignoring her protests regarding his weird behavior. At the police station, the little girl’s parents are reporting the incident at the same time that the homeless person reports that a guy offered him an ostrich plus a thousand bucks for his clothes and shopping cart.
However he took the things and ran. The description both victims give match and Detective Chilcoat becomes interested in the case, especially when a new report comes in saying the same guy started a fire at church. As Chilcoat announces he’ll go himself, an officer comes in with the infamous ostrich.
Meanwhile Elliot has put on the homeless man’s clothes and is doing the sixth challenge, which takes him to a very old house. For fifty thousand dollars, he must take the guy from 6B out for a cup of coffee before four p. m.
. Elliot thinks this is very easy but when he enters the apartment he's disturbed to find the guy dead in the tub. The voice explains the man self-deleted but this shouldn’t stop Elliot.
Determined to win the game, Elliot sprays freshener all over the body to cover up the rotting smell and drags him out of the apartment in the homeless guy’s shopping cart, making sure to put him in a position that makes him look alive. At the diner, he covers the body’s face with a hat and is rude to the waitress because she's taking too long to take his order. With only one minute left on the clock, a group of police officers enters the diner and sits right behind Elliot, making him nervous.
The waiter serves them coffee first, leaving Elliot with no choice but to steal a cup from them and put it on his table just in time. A message to his phone confirms he got the money, but now the officers are angry. Elliot apologizes and drops a bunch of money on the table while calling out the cops because they were putting alcohol in their coffees.
This makes them back away and Elliot gets to escape. Then he gets a call from the voice, who is so impressed by the police trick that he counts it as the seventh challenge. However the voice also says that Michael’s file is already being marked for review because the insurance company has dropped their support.
Michael comes out in a quiet street and finds a bus being driven by a silent person with a mask, so he gets in. Meanwhile at the diner, the police are getting the body and Chilcoat finds a card that fell from Ellot’s wallet when he paid. He sees a strange man called Vogler talking to the waitress, but he’s gone before he can interrogate him.
The waitress tells Chilcoat that Vogler claimed to be a reporter and left him a paper with his contact information, which Chilcoat takes for himself. Moments later Chilcoat visits Vogler at his trailer, but Vogler immediately runs away and gets behind a gate, which he locks up to stop Chilcoat from following him. He claims that the cops are working for “them” and tells Chilcoat to kill Elliot, then he leaves.
Chilcoat decides to search the trailer and finds lots of information about the game happening all over the country and even a symbol that appears to be the organization logo. Back to Elliot, he’s still on the bus when he gets the next call. The voice tells him to take out his library card, but Elliot doesn’t find it in the wallet.
This means the police knows his identity now and he may be facing ten years in prison. However the voice points out that if he finishes the game, he’ll make all the charges go away. Late at night, the bus drops Elliot at a motel and he goes to room eight, where he finds the organization logo on the keychain.
Inside the room there’s a nurse and a guy called John who recognizes him. It turns out they went to school together and John used to harass Elliot all the time. As the nurse takes out a saw, Elliot gets a call telling him to cut John’s arm off.
Elliot refuses to do it but when he asks John, the guy agrees to do it. This means he’s getting paid for this. Elliot gets ready to do it, but the nurse only gives John a local anesthetic so Elliot gets afraid of doing this with John awake.
Desperate to win, John starts insulting Elliot and reminding him of all the things he did to him and his brother in school, including pissing on Michael’s face. Eventually Elliot snaps and cuts the arm off in just one move while John yells in pain and blood is splattered everywhere. Afterward Elliot puts John in his car and takes him to the hospital, giving the arm in a bag to a nurse before leaving.
On his way out, he sees John’s brother and remembers he used to harass him too, so he grabs a chair and hits him with it twice until it breaks. Then he gets a message confirming that last act as challenge nine. In the meantime, the police are searching Elliot’s home to get a clue about his next destination.
A few hours later, Elliot makes it to the practice dinner for his wedding. He says hello to everyone but quickly moves to a corner, anxiously waiting for the next call. The voice finally comes in and says challenge ten will be for half million dollars.
When it’s Elliot’s turn to give a toast, he must destroy the room while singing “The Internationale Communist Anthem”. Everything breakable must be broken and flowers must be urinated on, also the song lyrics are in his jacket pocket. When the time comes for the speech, the police arrive looking for Michael, accusing him of public nudity.
Shelby’s mother makes all the guests leave to another room while Elliot worries over his brother, knowing this incident will send him to an awful institution. To distract the cops, Elliot decides to proceed with the challenge and he starts breaking glasses while singing the song. Michael uses the chance to run away and Elliot grabs a microphone stand to start destroying everything in the room, also throwing cupcakes at the cops.
When the officers try to stop him, Elliot threatens to self-delete to keep them at bay and proceeds to pee on the flowers. Then Elliot runs out of the building, putting up a chair to block the door. However the next call tells him that his eleventh challenge is to get arrested, so he has no choice but to move the chair and let the cops tackle him.
Later at the station, he’s interrogated for hours and a cop makes a list of all his crimes. Elliot sees things he didn’t do, making realize someone else is playing the game too. In the main office, Chilcoat learns on the news that Vogler’s RV was set on fire.
Chilcoat wants some time with Elliot, but his superior denies it. When Elliot is finally left alone, he breaks the bottom of the chair and waits for a cop to come in, using the chair piece to threaten him into giving him a gun. Then he uses the cop as a shield and demands to get his phone back.
The cops are already making a plan so Elliot gets into another room and locks the door while he gets the next call. The voice confirms there’s another player and if that guy finishes the thirteen challenges first, he gets the prize while Elliot gets jail. The cop uses the distraction to try to get his gun back, but Elliot accidentally fires it and the officer gets shot in the foot.
The other cops are about to bring the door down, so Elliot grabs a chair and jumps through the window, landing on a dumpster. His phone falls and he thinks of getting it back, but Chilcoat is aiming his gun at him from the window and there are more cops coming, so he has no choice but to run away. Minutes later Elliot steals a phone from a random guy on the street and holds him up, yelling that he knows he’s being watched and that they can call him to this new phone, but nothing happens.
At that moment a woman passes by and Elliot starts harassing her, thinking she’s part of the game too and following her to her home. After a few hours, Elliot finally accepts that the woman is just an innocent bystander and apologizes, but she suddenly changes her sorry face and gets serious. She goes outside and asks Elliot to fix the rope of her clothes hanger so it’s up again.
When he does son, he receives a text saying he finished challenge twelve and he was paid one million. At that moment a bunch of bikers are approaching the area and when Elliot takes a closer look, he realizes that the clothes hanger goes across the street and will decapitate the bikers. He immediately puts it down and the drivers cross safely, stopping nearby to confirm on the phone that they passed their challenge.
However the second player appears in the distance and puts up a second string, which sends Elliot running to warn the youngsters. He isn’t heard and when the bikers drive back for their next challenge, they fall for the trap and all of them get killed. Seeing the massacre, Elliot starts crying as he picks the ringing phone from a dead guy’s bag.
The voice congratulates him on his million dollars and starts reading questions from the audience, but Elliot throws the phone away and announces he doesn’t want to play anymore. Meanwhile Chilcoat finally finds Vogler at a bar and threatens him to share what he knows if he doesn’t want to be arrested. Vogler proceeds to show off all his research, explaining the rules of the game and revealing his wife played it some years ago, but she died during it after eating her dog.
Since then Vogler has been trying to find the organizers to no avail. Lots of famous incidents have been part of this game that started decades ago, including Kennedy’s assassination. Vogler explains the thirteenth challenge is always the same: the player must kill a member of their family.
Back to Elliot, he’s walking down the road when he suddenly hears a phone ringing with the voice’s ringtone. He starts searching for it among a crowd and notices a person running away, so he follows them into an amusement park. Suddenly the other player starts an ice cream truck and tries killing him, but Elliot dodges just in time.
The truck goes away and Elliot jumps on a random car to continue following them, finding another phone already waiting for him in the glove compartment. The voice reminds him that interfering with another player’s progress is against the rules and tries to tell him about the final challenge, but Elliot throws the phone out of the window. Eventually the truck stops and Elliot is shocked to find it at his father’s old house.
He rushes inside and finds Samson calmly having dinner. The toilet noise says someone else is in the bathroom, but it turns out to be Michael. Elliot is devastated to realize Michael has been the other player all along and he knows the final challenge: to kill a family member.
He has a weapon hiding in his bag ready to kill Samson as revenge for hitting them as kids. Elliot tries to calm him down and an argument ensues, only for Samson to interrupt them with a big reveal: he played the game back in the day and killed his wife to win it. He’s been living with the weight of his crimes since then and that’s why he’s become such a miserable man.
Furious, Elliot takes out the cop gun and tells Michael to wait in the other room. When he gets ready to shoot, Samson tells him he doesn’t want his son to fall for the game like he did and suddenly uses a knife to self-delete, keeping Elliot from winning. Now Michael is scared because he thinks Elliot will kill him instead so he reaches for his bag, claiming he only wants his medicine.
Assuming the worst, Elliot panics and shoots Michael first, immediately regretting it. He rushes to his brother’s side and Michael admits he only wants to win at something for a change before stabbing Elliot, who immediately pulls away. Michael reaches out to repeatedly stab him again as his bullet wound keeps on bleeding until he dies.
His phone plays a jingle and announces he lost all the money he made before declaring that Elliot is the winner. In the meantime, Chilcoat opens his truck with keychain that has the game logo, meaning he works for them. He’s killed Vogler for knowing too much and is now burning all his research.
Afterward he gets into Samson’s room with the intention of burning the bodies there too, only to be found by Elliot. Chilcoat explains that Elliot has nothing to worry about because his job is to cover up all the game crimes and get rid of the evidence, but Elliot is too eager for revenge and shoots Chilcoat on the spot. This disqualifies Elliot and he instantly loses the six million dollars.
Moments later, Elliot calls Shelby to make sure she’s alright. Shelby says someone called him and asked her to eat a fly but she didn’t do it, so Elliot sighs in relief.
