The Callisto Protocol: What Should You Upgrade First?

Early game upgrades

by Christian Bognar

The Callisto Protocol is one of the more challenging games of 2022, focused on dodging. With difficulty being on the higher end, picking the right upgrades at the beginning of the game is so vital that it can make all the difference whether you survive in the facility. At first, you won’t have access to many upgrades, but as you continue, you will unlock options as you receive more equipment. If you are wondering whether you should upgrade your Pistol, GRP, or Stun Baton first, we have you covered, as this guide will provide you with what we recommend.

Equipment to Upgrade First in The Callisto Protocol

You’ll unlock the Reforge, the upgrading hub, early on in the campaign. You will notice some slots have question marks, meaning you need to progress further to unlock. You unlock the GRP early, so players should use this guide right after receiving it. This guide recommends from first to last what to upgrade, and keep reading to find out how to receive Callisto Credits.

Stun Baton


The Callisto Protocol is all about inventory management while being able to maintain damage output upon the zombies in the facility. Since ammo is so scarce and you have infinite melee attacks, we recommend upgrading the Stun Baton first. This will be your primary attack when up close to enemies, and the stronger the weapon, the better chance you’ll have to survive against a horde of zombies.

BI-55 Pistol


Next, you should upgrade your pistol. A more accurate gun will get you out of a jam and help you make every bullet count. With leftover credits and after upgrading, make sure to buy ammo from the Reforge machine, so you are always prepared.



The last upgrade you should worry about is your GRP. Although it is helpful, only some environmental factors will make this ability as beneficial as many players have thought it would be. For example, there are only a few spike walls to throw zombies into. It is good enough from the start without an upgrade, where you will find yourself using it to create some distance between you and a horde of zombies.

How to Receive Callisto Credits?

To upgrade your equipment, you must collect Callisto Credits around the facility. These can be found by stomping on corpses, smashing glass windows, and in cabinets you find along your journey. Take these credits to the Reforge, your hub for buying ammo and upgrading.

Did you know that Striking Distance is offering a free skin pack? Read this guide to figure out how to claim the Founder’s Pack as your own!

The Callisto Protocol is available on PlayStation 5, PlayStation 4, Xbox Series X|S, Xbox One, and PC. 

- This article was updated on December 2nd, 2022

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