LUDO is the story of quirky characters and how their life gets interlinked in a series of bizarre circumstances. Alok Kumar Gupta aka Aalu (Rajkummar Rao) loves Pinky (Fatima Sana Shaikh) like crazy since childhood. Sadly for him, Pinky ditches him and marries Manohar Jain (Paritosh Tripathi). It's been three years since she's hitched and she even has a son. Yet, Aalu continues to love her. Pinky, however, is not happy with Manohar. She gets suspicious that he's having an affair.
However, he lies to her by saying that he goes out to meet his friend, Bhinder (Saurabh Sharma). One day, she follows him. He realizes he's being followed and hence has no choice but to drive to Bhinder's villa. Pinky realizes that Manohar isn't lying and leaves. Manohar then goes to meet his girlfriend, Sambhavi (Geetanjali Mishra). Minutes after he leaves, Sattu (Pankaj Tripathi), a dreaded gangster, arrives and kills Bhinder and his wife. Rahul Awasthi (Rohit Suresh Saraf), a sales executive in a hypermarket, who is kicked out of his house for non-payment of dues, happens to take refuge at the Bhinder villa at the same time.
While leaving, Sattu takes him hostage to his sprawling hideout in the middle of a river. While he's on his way, he kidnaps a person named Bhanu (Bhanu Uday) hostage as he has failed to repay him Rs. 90 lakhs that he owed. He also tells Bhanu's wife Asha (Asha Negi) that she should tell Bittu (Abhishek A Bachchan) to meet him. The next day, cops spot Manohar's car in Bhinder villa and conclude that he's the murderer. He's arrested by inspector Sukumar Sinha (Ishtiyak Arif Khan). Pinky ruins it by telling the cops that she saw Manohar entering the villa. Manohar, however, tells her at this point that he was with Sambhavi. He pleads her to meet Sambhavi and confess to the cops the truth and only then he'll be able to get out of custody.
Sambhavi, however, refuses to even admit that she has even met Manohar ever. With no other option, Pinky approaches Aalu for help. On the other hand, Asha meets Bittu. Bittu and Asha were married at one point and even have a daughter, Ruhi. Bittu used to work for Sattu but after he fell in love with Asha, he quit. Sattu didn't like it and he got Bittu arrested. Asha then married Bhanu and became the father of Ruhi. On Asha's request, Bittu goes to Sattu's hideout. At this point, Akash Chauhan (Aditya Roy Kapur) comes to meet Sattu. Akash finds out that a porn clip featuring him and Shruti Choksi (Sanya Malhotra), with whom he had a fling once, is viral. He first approaches inspector Sukumar Sinha. But he tells her to bring Shruti to file the FIR. Shruti is getting married in five days to a wealthy chap named Shekhar (Aman Bhagat) and when he meets her and tells the truth, she is livid. Hence, he approaches Sattu. Sattu assures him that his work will be done. As Akash leaves and Bittu enters, a loud explosion takes place there because of Rahul, who had gone to the kitchen to prepare tea and left the gas on. Akash and Bittu escape with minor injuries but Sattu gets grievously hurt. Yet, Sattu manages to take a nurse, Sheeja Thomas (Pearle Maaney) and Rahul hostage. What happens next forms the rest of the film.