The Resident Evil Zero Official Strategy Guide was a BradyGames guide book released in November 2002.
"BradyGames' Resident Evil Zero Official Strategy Guide provides a complete walkthrough, including strategies for inventory management, when to switch between Rebecca and Billy, solving complex puzzles, and more! Highly detailed maps depict every area and pinpoint all crucial items. Expert boss tactics provide methods to defeat each ghastly beast. Plus, complete item and weapon rosters, bestiary, character bios, game secrets, and much more!. This Signature Series guide features a special cover treatment, fascinating history of the Resident Evil series, an exclusive concept art section, and a giant hi-res. poster depicting the main characters."
— Official description.
This section begins with an outline of the history of the franchise up until the release of Resident Evil 0. Starting from page 4 is a transcription of Wesker's Report. This whole section has a timeline running at the bottom of each page, though has a number of errors in it. They will be listed below.
At the beginning, it incorrectly states that the Progenitor Virus (referred to here as the "Mother Virus") was discovered in the 1950s. It also claims that the first S.T.A.R.S. unit (referred to inaccurately as the Special Tactics and Rescue Squad) was founded in New York City in 1967. It goes on to say that S.T.A.R.S. was initially formed by the NYPD to tackle occult-related terrorism. Both this and the comment on S.T.A.R.S.' founding year were taken out of S.D. Perry's Resident Evil: The Umbrella Conspiracy.
Owing to a mistranslation in Resident Evil CODE:Veronica, mentions of the Umbrella subsidiary, Umbrella Pharmaceuticals instead call it "Umbrella Chemical", as seen in the "Mid-1970s (Estimated)" timestamp.
The "December 8, 1981" entry mistakenly claims that Alfred Ashford witnessed the construction of the training camp on Rockfort Island as a ten year old boy. CODE: Veronica, however, states clearly that the facility was completed in 1994. The claim in 1993 that chief Brian Irons used his position to cover-up missing person's reports relating to Umbrella's human experimentation may be speculative.
The "Winter 1998" entry marks the founding of Raccoon City's S.T.A.R.S. division. In Mainstream canon, this was actually in 1996. Barry is referred to as a former SWAT team member, though there is no mention of his former US Air Force career.
Later in 1998, Chief Irons' secretary is referred to as a woman, though the Japanese script to Resident Evil 2 uses male pronouns.
Finally, the timeline makes mention of "White Umbrella", again mistaking the S.D. Perry novels for Mainstream canon.
The CHARACTERS section starts with a mock police mission report. Unlike the timeline, it correctly refers to the team as "Special Tactics and Rescue Service" (as opposed to "Squad"). The location of the investigation is incorrectly referred to as the "Raccoon City Forest", rather than simply "Raccoon Forest". Tying into S.D. Perry's novelizations, it suggests Bravo Team is investigating a cult of crazed murderers (relating to the media-induced fear of satanic murder-cults in the 1990s), as opposed to a gang of cannibals and vicious dogs.
A mock newspaper cutting tying into S.D. Perry's novelization contradicts the timeline in the previous section. While the timeline suggested that the S.T.A.R.S. branch was founded in Raccoon at the beginning of 1998, the newspaper report - dated November 2 - says that the branch has existed for a "few short months". Since even Perry's Raccoon City was destroyed in October, this cutting must be from 1997 at the latest.
Albert Wesker's profile interestingly brings up his service as a chemical engineering officer in the US Army, albeit referring him as a "Tech Officer". Kenneth J. Sullivans brief profile brings up his gardening skills, an interresting titbit present in the biohazard 0 kaitaishinsho guide. The claim that Forest Speyer is equally good friends with Joseph Frost along with Chris Redfield, however, may be an invention of BradyGames. Kevin Dooley's profile is very inaccurate, claiming him to be a S.T.A.R.S. officer, when in fact he was an RPD pilot assigned to the mission. It adds on that he has taken part in rescue missions along the forest, before.
The Cerberus entry on page 27 states that the dobermans on the Ecliptic Express were being transported for B.O.W. testing and were infected by the leeches. However, as they are referred to as "Cerberuses" in here and the Capcom Japan-proofread biohazard 0 KAITAISHINSHO guide, they should have already been infected prior. A dog that has been infected by "t" unitentionally is a zombie dog.
The Crow entry on page 30 is somewhat inaccurate, suggesting that crows are hungry for humans. In actuality, their attack on people is more to do with the increased aggression various strains of the t-Virus bring, hence why the crows in the first game only reacted to loud noises.
The Plague Crawler entry on the same page mistakenly states that B.O.W. stands for "Biological Offensive Weapon. This is carried on with the Giant Spider entry on page 31.
The Hunter entry on page 33 is also inaccurate. It suggests that humans are transformed into Hunters by using the t-Virus to bond reptilian DNA into the human genome. In actuality, human embryos are experimented on, instead. It is correct that the Hunters were designed to be intelligent enough to understand and execute simple orders, though.
WEAPONS AMMO & FIRST AID (p35-41)
KEY ITEMS LIST (p42-50)
SURVIVING THE HORROR (p51-p59)
This section is devoted to providing gameplay help before the walkthrough, giving the basics and explaining the controls to new players.
The walkthrough is split heavily through each stage, with a section devoted to each objective the walkthrough wants you the player to perform. Each has a somewhat informal title, such as "Dinner is Served" (telling the player to go to the dining hall).
At parts of the walkthrough, it includes mock-diary entries by Rebecca Chambers, explaining the events of the story up until now.
Secrets of Resident Evil 0 (p136-138)
The Secrets section explains how much time it will take to complete the game in order to earn a particular rank, and states what bonuses are unlocked for each rank. For example, it says that between 3 hours 31 minutes and 5 hours is needed to earn an 'A' rank. However, it does not take into account how First Aid Sprays affect the rank.
A brief guide to "Leech Hunter" follows these, describing what can be unlocked in the main game for particular scores in the game. The guide suggests killing all the enemies first, then collecting the leeches.
Files and Documents (p139-146)
This section is designed to present each in-game file in a manner that appears like they are written on different pieces of paper, laid out on the book. It uses the English localization of the game, rather than independently translating it.
Concept Art Gallery (p147)
Most of these concept art pieces also appear in the Resident Evil Archives book that was translated and published by BradyGames in 2005. It includes brief descriptions of the differences in concept art, such as BradyGames speculating as to the intention of particular rooms that didn't appear in-game.
The Hunter test chamber in the facility basement is shown to have been simply a shooting range at one point in development a shooting range.
The section on the water treatment facility shows that the spiders were intended to appear much more, with cobwebs covering whole rooms in some of the art works.