As mentioned in the achievement title, you need to complete Claire's story on Standard or Hardcore with S-rank or higher. you
CAN'T get this on Assisted difficulty. you only need to get an S-rank or higher once, across scenario A and B for each character. doesn't matter if you go for it on Claire A or B scenario. However, you have 30 minutes less time on scenario B than you have on scenario A.
The main important thing to get an S or S+ rank is the completion time. not sure if the death counts but just in case quit to the main menu whenever you're about to die and it won't count as a death.
on Standard difficulty, you get few auto saves which is really helpful If you quit the game to avoid dying. On Hardcore, you can only save manually and there is no auto save. If you quit the game, you go back to your last save. Here is a list of how to get Infinite ammo and the required time to finish the game for S or S+ rank :
Standard Difficulty: Beat The Game Within 3:30:00 Hours for A Scenarios(New Game) or Within 3:00:00 for B Scenarios(New Game(2nd Run))
Rewards: S+ Rank/ Infinite Samurai Edge Pistol Ammo(Obtainable with S rank or higher) / Leon 'S.' Kennedy Achievement for Leon/ Sizzling Scarlet Hero Achievement for Claire
Hardcore Difficulty: Beat The Game Within 2:30:00 Hours for A Scenarios or 2:00:00 for B Scenarios
Rewards: S+ Rank/ Infinite LE 5 Submachine Gun Ammo (Obtainable with S rank or higher)
Infinite Combat Knife : Find and Shoot all 15 Mr.Raccoons
Infinite ATM-4 Rocket Launcher : Beat Leon's story on Hardcore difficulty with S+ rank
Infinite Minigun: Beat Claire's story on Hardcore difficulty with S+ rank
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If you don't care about ATM-4 Rocket Launcher/ Minigun Infinite ammo and only want the achievements, I suggest you do this on Standard. It is less pain. also you get Infinite Samurai Edge Pistol Ammo for both Claire and Leon and you can use it to beat the game on Hardcore for Hardcore Rookie / Hardcore College Student achievements.
NOTE: If you want the S+ rank
DO NOT save more than 3 times. doesn't matter what difficulty you are playing on. This will restrict your rank to S and you can't get the S+. however, S-rank is enough for the achievements.
NOTE: Using any of the 5 Infinite ammo weapons will restrict your rank to S.
NOTE: If your mind is not clear about what to do next, progress your game with a guide. here is a link to Resident Evil fandom. you can click on any item you don't remember where to find and see where It is. (
https://residentevil.fandom.com/wiki/Category:Resident_Evil_...)
Also, try to find the puzzle solutions online and don't attempt to solve them yourself. they can take an unnecessary amount of time. I personally wasted 6 minutes on the Jail electric panel.
NOTE: Manage Your Recourses. Stock Up Ammo. you don't get much near the end and you have at least two boss fights to kill. I had to go hand to hand with Super Tyrant because I had only 10 bullets left and I needed them to avoid his Insta kill move later.
NOTE: I suggest you do this on A Scenarios. because you don't have to deal with Stage 5 G at the end.
NOTE: Time won't pass when you pause. you can see the timer on the top right corner of the screen.
UPDATE: Time DOES pass when you are using the item box or map. pause the game
ONLY using the menu button.
Alright, guys, I did my best to try and explain everything. this is one of my few long solutions, so forgive me If there is anything you don't like about it. If you had any further question please ask. Happy Hunting