Before writing Fate/Zero, Urobuchi was going through a difficult period as a writer where he could no longer write as he once had in the past. He especially had trouble with the endings of his works. He felt he was trapped in the stereotype that the only true creative activity was something that had to express his own thoughts. He didn't believe that he could adapt a story that he hadn't created without being insincere. Writing Fate/Zero helped him reaffirm the pleasure of simply writing, allowing him to concentrate on writing stories merely for entertainment without allowing too much pressure to be placed on himself.
Much of the process was supervised by Kinoko Nasu, who looked over the draft for the new characters and the plot. He admits that about ninety percent were accepted immediately due to being Nasu's ideas in the first place. All of the characters were named by Nasu except for Hisau Maiya, which was suggested by Urobuchi.
Urobuchi favourite scene was the reincarnation of the true Gilgamesh. Urobuchi wanted to dedicate more pages to Kariya Matou and Sola-Ui Nuada-Re Sophia-Ri. But it probably wouldn't turn out to be a happy scene if he were to write it.
- Phantom: The Animation (2004) (OVA, producer, wrote original scenario)
- Blassreiter (2008) (TV anime by GONZO, Scriptwriter for ep: 10-12, 15-17, 22-23)
- Phantom ~Requiem for the Phantom~ (2009) (TV anime adaptation of his visual novel story by Bee Train. Wrote scripts for episodes 6, 18, and 25)
- Puella Magi Madoka Magica (2011)
- Fate/Zero (2011) (TV anime by Ufotable, original creator)
- Psycho-Pass (2012)
- Suisei no Gargantia (2013) (TV Anime by Production I.G, original creator)
- Aldnoah.Zero (2014) (original creator)
- Psycho-Pass 2 (2014)
- Phantom of Inferno (2000) (visual novel by Nitro+, scriptwriter, illustrated by Kimi Yanoguchi)
- Vampirdzhija Vjedogonia (2001) (visual novel by Nitro+, scriptwriter, illustrated by Higashiguchi Chuuou)
- Kikokugai - The Cyber Slayer (2002) (visual novel by Nitro+, scriptwriter, illustrated by Higashiguchi Chuuou)
- Saya no Uta (2003) (visual novel by Nitro+, scriptwriter, illustrated by Higashiguchi Chuuou)
- Jouka no Monshou (2003) (a short “fanfiction” Visual Novel by Gen Urobuchi, illustrated by Higashiguchi Chuuou. It takes place in the world of Equilibrium, which Urobuchi is a fan of)
- Zoku Satsuriku no Django (2007) (visual novel by Nitro+, scriptwriter, illustrated by Niθ)
- Hakumou no Dendoushi (2004) (novel, illustrated by kamiwata)
- Fate/zero (2006-2007) (novel, prequel to Fate/stay night, collaboration with TYPE-MOON)
- Black Lagoon novels (2008-2011) (novel, illustrated by Rei Hiroe)
- Eisen Flügel (2009) (novel, illustrated by Higashiguchi Chuuou)
- Kin no Hitomi to Tetsu no Ken (2011) (novel, illustrated by Yun Kouga)
- Kamen Rider Gaim (2013-2014)
He is noted for his Reality Marble, Dead End Catharsis: Heaven & Hell Drop (地獄極楽おとし, ?), which lowers the luck of all characters in his stories by one rank, but the effect is lessened somewhat in Fate/Zero due to the "Kinoko Dimension" also taking place in Fuyuki. It lowered the effect, making it so all those who can survive will definitely live, a very reasonable, considerate measure that happens very rarely in Urobuchi's world.
- ↑ Interview: Fate/Zero Screenwriter Gen Urobuchi
 ALL OVER/Zero - Fate/Zero Exchange of Questions and Answers, p.025
Questions 20: What's Urobuchi's favorite scene? Also, if it exists, please tell us about something you didn't finish. [T]
Questions 20: What's Urobuchi's favorite scene? Also, if it exists, please tell us about something you didn't finish. [ Taitō · Mountain of Mash Tree ]
Gen: Even though it's for my own enjoyment, probably the great revival of the true Gilgamesh. I also wanted to dedicate more pages to Kariya and Sola-Ui. Uh... but it probably wouldn't turn out to be a happy scene if I were to write it. Looks like Sola-Ui really is someone who can truly shine only in doujinshi.
 ALL OVER/Zero - Fate/Zero Exchange of Questions and Answers, p.023-024
Questions 09: Why is my luck stat curiously low... it seems even lower than when I fell to the dark side 10 years later. What kind of curse is this? [T]
Questions 09: Why is my luck stat curiously low... it seems even lower than when I fell to the dark side 10 years later. What kind of curse is this? [ Fuyuki · King of Knights ]
Nasu: In Zero, due to the effect of Urobuchi Gen's Reality Marble, Dead End Catharsis: Heaven and Hell Drop, all character's luck have been lowered by one rank.
Gen: But at the same time Kinoko Dimension also took place in Fuyuki, so those who can survive will definitely live. Something this reasonable happens very rarely in Urobuchi's world, so it's already a very considerate measure.