The developer of The Last Of Us Part 2 will be making some major changes to the game with one of it being the new upgrade system and here is how it works.
While the upgrades will make Ellie stronger, it is not everything it does as the developer wanted it to also change the way you play the game depending on your style. One example that was given was the ability to hold your breath while aiming, this is not something that Ellie will be able to do in the start but can be learn through the system upgrade.
Some crafting recipes like the silencer can only be learned from the upgrade system as well so at the end of the day, the Ellie that you have might have very different capabilities than the Ellie that your friend has and that is what keeps the game so interesting.
This are only some of the changes that were made as the developer also highlighted the addition of dogs and also the upgrades that the AI will have this time around.