During School Life, the player can explore the school grounds in first-person perspective, with more areas of the academy becoming available as the game progresses. Whilst in one of the various rooms, players move a crosshair cursor which is used to initiate conversations with characters or examine parts of the environment. Examining certain objects yields Monokuma Medals, which can be used in a capsule machine in the school shop to unlock presents. School Life is divided into two sections; "Daily Life" and "Deadly Life". In the Daily Life sections, players converse with various characters and move the plot along. Certain comments can be 'reacted' to in order to reveal new information. In designated 'Free Time' segments, players can choose to hang out with specific characters and give them presents, which in turn reveals more information about them and unlocks various Skills that can be used in the Class Trials. When a crime scene is discovered, the game shifts to the Deadly Life section, in which the player must search for clues throughout the academy. Evidence and testimonies gathered are stored in the player's e-Handbook, where players can also save their game. When all possible evidence is located, the game moves on to the Class Trial. Prior to a Class Trial, players can assign any Skills they have unlocked, which can assist them during gameplay.
The Class Trials are the main section of the game, in which the students must discuss amongst themselves who the culprit is. With the exception of occasions where the player must answer a multiple choice question or present a piece of evidence, Class Trials consist of four main styles of gameplay: Nonstop Debate, Hangman's Gambit, Bullet Time Battle and Closing Argument. The most common of these is the Nonstop Debate, where characters will automatically discuss their thoughts on the case, with potential 'weak points' highlighted in yellow. During these sections, the player is armed with "Truth Bullets", metaphorical bullets containing evidence relevant to the discussion. In order to break the debate, the player must find a lie or contradiction amongst the weak points and shoot it with a bullet containing the evidence that contradicts it. Players can also silence disruptive purple chatter to earn extra time and utilize a Concentration meter to slow down the conversation and make shots more easily. These sections become more difficult as the game progresses and more possible weak points are added, with later trials occasionally requiring the player to use one remark as ammunition against another.
Hangman's Gambit is a shooting puzzle section in which the player must shoot down specific letters that spell out a clue. Bullet Time Battle is a one-on-one debate against another student featuring rhythm style gameplay. As the opponent makes remarks, the player must press buttons in time to the beat to lock onto the remarks and shoot them down. Finally, Closing Argument is a puzzle in which players piece together a comic strip depicting how a crime went down. The player's Influence amongst the other students is represented by hearts, which is reduced whenever the player makes errors in shooting contradictions or presenting evidence and is slightly replenished when correct evidence is presented. The game ends if the player loses all of their Influence, or if they run out of time during a segment. At the end of a trial, players are ranked on their performance, with additional Monokuma Medals awarded for high ranks.