Rule No. 1

Rule #1
Film poster
Traditional	第一誡
Simplified	第一诫
Mandarin	Dì Yī Jiè
Cantonese	Dai6 Jat1 Gaai3
Directed by	Kelvin Tong
Produced by	Lam Tak Candy Leung
Screenplay by	Kelvin Tong
Story by	Kelvin Tong John Powers
Starring	Shawn Yue Ekin Cheng Stephanie Che Fiona Xie
Music by	Joe Ng Alex Oh
Cinematography	Venus Keung
Edited by	Azrael Chung
Production company	Fortune Star Entertainment Mediacorp Raintree Pictures Scorpio East Pictures Dream Movie Entertainment Overseas Boku Films
Distributed by	Fortune Star Entertainment
Release date	4 September 2008 (2008-09-04)
Running time	95 minutes
Country	Hong Kong
Language	Cantonese
Box office	US$932,596

Rule #1 is a 2008 Hong Kong horror film directed by Kelvin Tong and starring Shawn Yue, Ekin Cheng, Stephanie Che and Fiona Xie.

While on duty during an assignment, young sergeant Lee Kwok-keung (Shawn Yue) shot and killed serial killer Chan Fuk-loi (Ben Yuen) after he had his four limbs crippled by Chan. Forty nine days later, Lee woke up in the hospital but his testimony was not recognized by the police because of his description which contains some supernatural things. His superior then transferred him to the Miscellaneous Affairs Department to let him rest.

Unlike the heroic duty of fighting crime and protecting citizens, the Miscellaneous Affairs deals with unusual cases, which is intriguing and makes people feel lost. The head of the Miscellaneous Affairs, Inspector Wong Yiu-fai (Ekin Cheng), is an eccentric and beer-guzzling man. Wong and Lee work together for the Miscellaneous Affairs to solve an unusual request: to eliminate the fear of every citizen seeking help. While carrying out their duties, Wong pretentiously tells Lee the first commandment of the Miscellaneous Affairs: There are no ghosts in this world! In fact, this first commandment is just a lie. The primary task for the Miscellaneous Affairs of dealing unusual cases is to conceal supernatural incidents to the community to reduce social panic.

Just when Wong and Lee take over the Saint Austina High School Massacre case, the ghost of Chan Fuk-loi possess into the body of Lee's wife, May (Fiona Xie), while Lee was also possessed later. The possessed Lee shoots and kills Wong and other colleagues and then makes up his own story to deceive the police.