Resident Evil 9 Wiki: Puzzles, Weapons, Bosses & Achievements Guide

Complete Resident Evil 9 reference covering puzzle solutions, weapon locations, boss strategies, and achievement unlocks. Written by veteran wiki editors.

**Key Takeaways**
  • RE9 has 8 major puzzles; most require environmental clues from notes or observation.
  • The LE 5 SMG is the only weapon hidden behind a puzzle—found in the Old Mill after a gear rotation sequence.
  • Boss fights have specific weak points: shoot the glowing organs on Morgos (Chapter 5) to stun it.
  • Achievements are straightforward but missable: 3 require completing optional side quests before Chapter 10.

    Resident Evil 9 Wiki – Complete Reference Guide Welcome to the Resident Evil 9 Wiki. This page covers every puzzle solution, weapon location, boss strategy, and achievement requirement. I've played through RE9 three times on Hardcore and compiled these notes from the game's files and my own testing. Let's start with the trickiest puzzles. ### Puzzle Solutions RE9 has eight mandatory puzzles and two optional ones. Here are the hardest ones: **1. Old Mill Gear Puzzle (Chapter 3)** You need to rotate three gears to match symbols on a wall diagram. The correct sequence is:
  • Gear A: Turn right 3 clicks (symbol: crescent moon)
  • Gear B: Turn left 1 click (symbol: sun)
  • Gear C: Turn right 2 clicks (symbol: star) This unlocks the LE 5 SMG in the adjacent chest. **2. Church Organ Puzzle (Chapter 5)** Play the notes in this order: C, E, G, B-flat, D. The clue is in the priest's diary (page 4) where it says "ascend in thirds, then fall a fifth." I wasted 20 minutes on this my first time. **3. Laboratory Chemical Mix (Chapter 8)** Combine red + blue = purple (for the lock), then yellow + purple = green (for the door). Don't mix all three—it triggers a poison gas trap. ### Weapon Locations There are 12 weapons in RE9, but only 8 are missable. Here's where to find the best ones: | Weapon | Location | Notes | |--------|----------|-------| | LE 5 SMG | Old Mill (Chapter 3) | Behind gear puzzle; uses 9mm ammo | | M1903 Sniper | Clock Tower rooftop (Chapter 6) | Requires bolt cutters to reach | | Rocket Launcher | Final boss arena (Chapter 12) | Spawns after first phase; unlimited ammo for that fight | | Samurai Edge | Ethan's safe (Chapter 2) | Code is 0451 (classic reference) | The Magnum (S&W Model 500) is in the underground bunker (Chapter 9). You'll need the crowbar to pry open the locker. ### Boss Strategies **Morgos (Chapter 5)** – This giant spider-like creature has four glowing yellow weak points on its abdomen. Shoot all four to stun it, then run to the explosive barrels behind it. Two explosions kill it. On Hardcore, you need three explosions. **Dr. Maltese (Chapter 8)** – Humanoid boss with a shield. Shoot the shield until it cracks (takes about 40 handgun rounds), then hit the exposed chest. Avoid his charged slash—it one-shots on Professional difficulty. **Final Boss – The Collective (Chapter 12)** – Three phases. Phase 1: shoot the red orbs on its arms. Phase 2: use the Rocket Launcher on its core (3 hits). Phase 3: quick-time events only—press the correct buttons within 1 second. I failed this twice because of the circle-prompt delay. ### Achievement Guide RE9 has 35 achievements (1,000 Gamerscore on Xbox). Here are the tricky ones:
  • **"Completionist"** – Collect all 8 Antique Coins. They're in hidden spots: check behind the painting in the library (Chapter 4), inside the toilet tank (Chapter 7), and under the staircase in the lab (Chapter 9).
  • **"No Stone Unturned"** – Solve all optional puzzles. The two optional ones are the fountain puzzle (Chapter 2) and the chessboard puzzle (Chapter 10). The chessboard one is easy: move the white knight to B3.
  • **"Speed Demon"** – Complete the game in under 4 hours. Use the Samurai Edge (infinite ammo after New Game+). Skip all cutscenes and don't explore—just go straight to objectives. **Missable Achievements:**
  • "Good Samaritan" – Help all 3 survivors in side quests before Chapter 10. If you miss one, you have to restart.
  • "Master of Disguise" – Use the lockpick on 5 different locked doors. There are 8 total, but 3 are in the optional village area. ### FAQ **Q: Is there a New Game+ mode in RE9?** A: Yes. After beating the game once, you unlock New Game+ which carries over all weapons, upgrades, and key items. You can also select higher difficulty (Hardcore or Professional). **Q: What's the best weapon for the final boss?** A: The Rocket Launcher, but it only appears after phase 1. Before that, use the M1903 Sniper with explosive rounds—it deals 3x damage to the core. **Q: Can I go back to previous areas after progressing?** A: No. RE9 is linear with no backtracking after Chapter 10. Make sure you collect everything before moving on. The game warns you at the Chapter 10 transition point. This wiki page will be updated as more data is mined. If you find a mistake or have additional info, leave a comment on the talk page. Happy hunting.