If you’ve managed to survive the numerous horrors of Resident Evil 2‘s earliest locations, you’ll have eventually found your way to the NEST, Umbrella’s top-secret subterranean laboratory.
To proceed further into its depths, you’ll need to upgrade your wrist-mounted keycard. If you’re looking to acquire the Level 3 card, you’ll first need to gain access to certain locked sections of the lab’s greenhouse: a machine used to mix herbicide, and a hatch leading down to the section’s lowest level.
Let’s sort out the hatch first. Before you can enter the codes in the greenhouse’s observation room, you’d normally need to venture into the greenhouse itself, avoiding the plant-like zombies in the process. With our guide, however, you can skip the harrowing run to the codes’ locations.
The hatch’s code changes between your First and Second Runs. Here’s the code you’ll need to use in your first playthrough:
And here’s the one for Second Run players:
Unlocking the herbicide machine is a little trickier. The code was, at some point, displayed prominently atop the machine’s casing, but part of it has been scratched off.
To uncover the full code, you’ll need to first unlock the hatch, proceed into the basement area and find a DNA helix statue. Its location differs across playthroughs (it’s on a table by the vending machines in your first game, and in the lab room outside the Low-Temp Testing room during a Second Run), as does the code it gives you when you examine its base.
This is the code for a first game:
And this is what to enter on a Second Run:
This can be one of the trickier puzzles in Resident Evil 2, especially if your memory is as terrible as mine. I had to resort to taking screenshots on my PS4 to flip between as I entered the codes. Thanks to our handy guide, you won’t have any trouble!