Tubocurarine chloride is a deadly muscle relaxant found in the bracelets in Zero Escape: Virtue's Last Reward. It eventually shuts down the respiratory system inside of the recipient's body, killing them by asphyxiation.
Virtue's Last Reward
In the Nonary Game: Ambidex Edition, each player's bracelet has tubocurarine inside it. If a player breaks any of the rules in the game, the player is injected with Soporil, which makes them fall asleep. Nine minutes later, the tubocurarine is injected, shutting down their respiratory muscles and resulting in immediate death. According to Zero III, the Soporil is used with the tubocurarine to make the victim's death as painless as possible.
There are a few bottles of tubocurarine inside a cabinet full of medicine in the Infirmary, along with an injection gun.
During Luna's route, Clover visits the Infirmary behind the yellow Chromatic Door and finds the tubocurarine and the injection gun. Clover uses an injection gun loaded with a vial of tubocurarine to accidentally "kill" Luna while confronting her about Alice's death.
Later, Tenmyouji and Clover are killed by tubocurarine, since Dio handcuffed them to a sink. This prevented them from reaching the white Chromatic Doors before they closed, leading to Tenmyouji and Clover being penalized. Before her death, Clover wrote Dio's name on her left thigh in order to tell Sigma, Phi, and K who killed her. However her legs slumped together when she died and the message was transferred to her other leg. It now read 016. The numbers 016 were the last numbers of Luna's GAULEM ID, which made Sigma and Phi suspicious of her when they found out she was a robot.
According to Clover, neostigmine is capable of countering tubocurarine. She learned this from her brother after the Second Nonary Game. An injection gun loaded with neostigmine is found in the treatment center safe. Clover takes possession of the neostigmine gun, but is unable to use it after succumbing to Radical-6 along with the rest of her companions.
Dio's bracelet is broken, leaving Phi and K unable to enter the white Chromatic Doors. Sigma, remembering the neostigmine, runs to the treatment center to collect it from Dio's corpse. He gets back to Warehouse B just in time to see the doors close, causing K, Phi, and Sigma to be injected with Soporil. Since K's armor cannot be penetrated by the injection gun, Sigma uses it on Phi, saving her. Phi calls Sigma an idiot for not using the neostigmine on himself, to which he replies that he hadn't even thought of that. Phi then falls unconscious. Sigma crawls towards K and has a conversation with him, and realizes that his armor had been unlocked. After Sigma removes K's mask, both of them are injected with tubocurarine, resulting in their deaths.
- It is possible that Tenmyouji used neostigmine in Luna Game Over 1 to counteract the tubocurarine, as he escaped with Quark despite having only 4 BP. However, this has not been confirmed.