Executions

Execution or often dubbed as Punishment appears in Danganronpa: Trigger Happy Havoc, Danganronpa 2: Goodbye Despair, Danganronpa Another Episode: Ultra Despair Girls, Danganronpa 3: The End of Hope's Peak Academy - Side Despair, and Danganronpa 3: The End of Hope's Peak Academy - Side: Future.

In Danganronpa and Danganronpa 2, they happen at the end of every Class Trial when someone is voted guilty. In Danganronpa Another Episode, they mostly happen after every boss battle. In Danganronpa 3, they are a punishment for breaking the forbidden action/NG Codes.

Danganronpa 3 - Side: Despair
The genesis of executions is revealed in Danganronpa 3 - Side: Despair. Junko Enoshima decided that an execution which utilizes things the victim is familiar with and finds comfort in their daily life from will bring about the greatest despair. Furthermore, she realized that broadcasting it will help bring about despair to people related to its victim. First tested a basic form by simply using a Trustee's favorite food to kill him, she refined it into the familiar form of talent-oriented execution by the time of Parade: a real-life dungeon crawler to execute Chiaki Nanami the Ultimate Gamer; its broadcast was also used to turn Class 77-B into Ultimate Despair.

Danganronpa and Danganronpa 2
Executions are used at the end of every class trial once everyone has picked someone to be guilty. If the students successfully pick the blackened, they and they alone will be executed. If they pick wrong, everyone except the blackened will be executed.

However, there are some exceptions to this rule. In Danganronpa, Jin Kirigiri is executed in the Prologue before the killing game began. In Chapter 4, a special guest for the execution was used, as the blackened was also the victim, via suicide, and Monokuma wanted to get rid of it as it had accessed the school's computer network. In Chapter 5, Monokuma set up a show trial as the Mastermind was annoyed with Kyoko Kirigiri attempting to find the truth. In both variations of the execution, although technically the students are incorrect, Monokuma accepts the results as valid, as the mastermind wants to keep the others alive to bring despair to the world. Likewise in Chapter 5 of Danganronpa 2, Monokuma decides to execute Monomi along with AI Chiaki Nanami, as Monomi and Chiaki were both part of the Future Foundation, Monokuma's enemy, and that Monokuma found Monomi's interference annoying.

Continuing with the use of things familiar with the victim, executions are ironically designed based on the talents of the person being executed, their feelings at the time, or settings they are familiar with. The only exceptions to this seem to be Excavator Destroyer and Blast Off!.

Besides the formal execution used in every class trial, students who violated the rules applied by Monokuma will immediately executed. This installment used when Mukuro Ikusaba under Junko's disguise executed via Spears of Gungnir after she used violence toward Monokuma.

Danganronpa Another Episode
In Danganronpa Another Episode, executions are done differently. They are used to symbolize a character's death but usually occur at the end of a boss battle. The person controlling the robot will be executed, either by the Monokuma Kids or the robot itself in an explosion.

At the end of Danganronpa Another Episode, it was revealed that all of the people executed after boss battles survived and were now battling the Monokuma robots.

Danganronpa 3 - Side: Future
In Danganronpa 3 - Side: Future, executions occur when Rule #3 of the Final Killing Game is broken. On each players' arm is a bangle, which has a forbidden action on it, also known as an NG Code. If that action is performed, then a lethal dose of poison is administered and the player is killed.

Danganronpa: Trigger Happy Havoc

 * Jin Kirigiri (Prologue/Episode 01)
 * Mukuro Ikusaba (Chapter 1/Episode 02)
 * Leon Kuwata (Chapter 1/Episode 03)
 * Mondo Owada (Chapter 2/Episode 05)
 * Celestia Ludenberg (Chapter 3/Episode 07)
 * Alter Ego (Chapter 4/Episode 09, "special guest")
 * Kyoko Kirigiri (Chapter 5, Bad End)
 * Makoto Naegi (Chapter 5/Episode 11, True End, successfully interfered by Alter Ego)
 * Junko Enoshima (Chapter 6/Episode 13)

Danganronpa 2: Goodbye Despair

 * Monomi (Prologue)
 * Teruteru Hanamura (Chapter 1)
 * Peko Pekoyama (Chapter 2, unsuccessfully interfered by Fuyuhiko Kuzuryu)
 * Mikan Tsumiki (Chapter 3)
 * Gundham Tanaka (Chapter 4)
 * Chiaki Nanami and Monomi (Chapter 5, executed together)
 * A.I. Junko Enoshima (Chapter 6, as the Forced Shutdown activated)

Danganronpa Another Episode: Ultra Despair Girls

 * Komaru Naegi (Prologue, survived)
 * Yuta Asahina (Chapter 1)
 * Masaru Daimon (Chapter 1, survived)
 * Jataro Kemuri (Chapter 2, survived)
 * Kotoko Utsugi (Chapter 3, successfully interfered by Genocide Jack)
 * Nagisa Shingetsu (Chapter 4, survived)

Danganronpa 3: The End of Hope's Peak Academy - Side: Despair

 * Unnamed Hope's Peak Academy Trustee (Side: Despair #06)
 * Chiaki Nanami (Side: Future #10)

Danganronpa 3: The End of Hope's Peak Academy - Side: Future

 * Daisaku Bandai (Side: Future #02)
 * Sonosuke Izayoi (off-screen; Shown in Side: Future #09's flashback)
 * Koichi Kizakura (Side: Future #08)
 * Kyoko Kirigiri (Side: Future #09, survived)

Prior to the Tragedy

 * Chiaki Nanami's Punishment (Side: Despair #10)

Killing School Life

 * Blast Off! (Prologue/Episode 01)
 * Spears of Gungnir (Chapter 1/Episode 02)
 * The 1,000 Blows (Chapter 1/Episode 03)
 * The Cage of Death (Chapter 2/Episode 05)
 * The Burning of the Versailles Witch (Chapter 3/Episode 07)
 * Excavator Destroyer (Chapter 4/Episode 09)
 * After School Lesson (Chapter 5, both Bad End and True End/Episode 11, only True End)
 * The Ultimate Punishment (Chapter 6/Episode 13)

Killing School Trip

 * Deep Fried Teruteru (Chapter 1)
 * One Woman Army (Chapter 2)
 * Bye-Bye Ouchies (Chapter 3)
 * Gundham Tanaka Stampede (Chapter 4)
 * Please Insert Coin (Chapter 5)
 * Forced Shutdown (Chapter 6)

Demon Hunting

 * Helicopter Crash Episode (Prologue)
 * Swimming Explosion Episode (Chapter 1)
 * Punishment of the Hero (Chapter 1)
 * Punishment of the Priest (Chapter 2)
 * Punishment of the Fighter (Chapter 3)
 * Punishment of the Sage (Chapter 4)

Final Killing Game

 * NG Code Poisoning (Side: Future #02, #08, and #09)