Survival in The Last of Us Part 1 will come down to equal parts stealth, skill, and resource management. As Joel and Ellie go farther and farther west, the challenges they face will only become more daunting, asking more from the player in terms of all of these attributes. Aside from upgrading Joel himself with a few skills, the main way you will keep up with the harsher conditions of the game is through upgrading your weapons. However, you will realize very early on that many upgrades are locked.
The only way to fully upgrade your arsenal is by finding five toolboxes. These simple tools all unlock a new level of upgrades for your weapons, but just like anything else in The Last of Us Part 1, they're very easy to overlook as you're sneaking through an area or just admiring the amazing environments. Since there's no backtracking in this game, missing one means you won't be able to max out any upgrades on your first playthrough, so make a note of all the toolbox locations in The Last of Us Part 1 listed here.
First tool location
The first toolbox won't come until you make it to Chapter 4 of the game, called Bill's Town. After navigating his traps (or at least most of them), you will meet up with Bill and eventually make your way to his home base of sorts in an abandoned church. Here, he will show you how to make the very useful Nail Bomb item, but don't leave the area to test it out just yet. Before you leave the basement, check the back corner for a shelf with the red toolbox sitting on it.
Second tool location
Very early in Chapter 5, Pittsburgh, you will be attacked by a group of survivors. After taking them out, you will need to lift up a garage door to progress. Once inside, look to the shelves immediately to your left for the toolbox.
Third tool location
Moving on to Chapter 6 now, follow the main path through the sewers until you get to the point where Ellie repairs a generator and Henry pulls you out of the water. Follow the tunnel forward, but watch for a side path on your left side. Take the path to a small room with the toolbox lying on the ground.
Fourth tool location
Back in school during Chapter 8, The University, go all the way into the science building but don't go up to the second floor quite yet. At the end of the hall, just past a vending machine, is a locked door you will need a shiv to pry open. Use one, get inside, and the toolbox will be sitting front and center on one of the lab tables.
Fifth tool location
Our final toolbox is waiting in Chapter 10. After an awkward start, eventually, you will come to the infamous giraffe scene and then trigger a cutscene. After it ends, you will be in the abandoned FEMA camp. Look for the open tent nearest the bus station and go inside. Directly to the right of the entrance is a table with the final toolbox sitting on top.
