
The release of Resident Evil 9 (AKA Resident Evil Requiem) is just around the corner this month. The survival horror title has been massively hyped by the return of both Leon S. Kennedy as a playable character and Raccoon City as a desolate, ruined location. While RE9 promises new locations, enemies, and characters, there’s also decades of series baggage and character development that players may be expected to know going in.
With these expectations in mind, here’s every Resident Evil title that will be essential to fully understanding Resident Evil 9, especially the story surrounding Leon and Grace. For any players unfamiliar with Resident Evil as a series, it might seem prudent to play the games that precede RE9, like Resident Evil 7 and Resident Evil 8: Village.
Numerically, this makes sense, but plot-wise, the story that took place over the course of those games and their DLC was almost entirely separate from the characters and sprawling story that began with Resident Evil 1, besides the appearances of Chris Redfield to shoot big guns at giant monsters near the end of both games. The following list will relate more directly to the plot and characters of Resident Evil 9: Requiem.
Resident Evil 2

Players could kick things off by playing the game that started it all, Resident Evil, but it’s just as easy to start with Resident Evil 2. While there’s always the original 1998 version, character models and overall characterization of people and events in Resident Evil 9 will likely mesh better with the remake of Resident Evil 2, which released in 2019.
This is the very first game to introduce Leon S. Kennedy, which makes it essential for understanding him throughout the Resident Evil series. A rookie cop traveling to Raccoon City to start his new job, Leon has the worst first day imaginable as the city succumbs to the Umbrella Corporation’s rampant T-Virus. Other notable series characters are also first introduced in RE2, including Ada Wong, a femme fatale who has a strong likelihood of appearing in some form in RE9.
Resident Evil Outbreak 1 & 2

Outbreak, File 1 and 2, aren’t mainline entries in the Resident Evil series, but the characters involved will be extremely relevant to Resident Evil 9, which makes this (unfortunately) important to know. The game was a multiplayer experiment of the early 2000s, which means that it’s almost impossible to play now. However, watching a playthrough online would serve just as well to understand Resident Evil 9.
The most important character in both File 1 and 2 is Alyssa Ashcroft, an investigative reporter who survived the outbreak and later went on to have Grace Ashcroft, the protagonist of Resident Evil 9. As revealed in the trailers for RE9, Alyssa’s death is a traumatic life event for Grace and will likely be heavily connected to the story.
Resident Evil 4

Skipping Resident Evil 3, players can head straight into Resident Evil 4, which once again features Leon, this time on a solo mission as he rescues the President’s daughter from a parasite-infested village. RE4 is one of the best of the series, especially the 2023 remake, but the storyline following Leon and his development since the events of Raccoon City will be crucial to understanding his character in Resident Evil 9.
Resident Evil 6 [Optional]

Resident Evil 6 is the most recent mainline title (besides the recent remakes) to feature Leon as a protagonist. While the plot might not connect directly to Resident Evil 9 – and its reception among fans is critical at best – it does continue Leon’s story, for better or worse. Since the game follows multiple characters and is often repetitive in its gameplay, players can instead opt to watch Leon’s sections in any playthrough online to understand where the series last left him.
Resident Evil: Death Island
Though not a game, players can also consider watching Resident Evil: Death Island. This 2023 film is the most recent appearance of Leon, alongside the entire pantheon of iconic Resident Evil characters like Chris Redfield, Jill Valentine, and Rebecca Chambers. The story takes place in San Francisco, as the cast investigates another Umbrella Corporation outbreak near the city.