O/S upgrades are special boosts in System Shock 2 Remastered that enhance your overall abilities in addition to your existing stats. There are quite a few upgrades that are available to you, though the upgrade stations are quite rare and only four can be found in the entire game.
Apart from that, it all comes down to the player’s choice of OS upgrades they want to pursue. Here’s a detailed discussion on all the O/S upgrades you can unlock in System Shock 2 Remastered.
System Shock 2 Remastered: All O/S upgrades

There are a total of 16 O/S upgrades that you can unlock during your journey through System Shock 2 Remastered. The problem with unlocking is that you will need O/S Upgrade units to get them. However, two are available in the early game, one can be found around halfway through the game, and the final one towards the very end.
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This means you should get the upgrades you really want early, and then focus on the rest once you reach the endgame. Here are all the O/S upgrades that you can unlock in the game:
- Strong Metabolism: You gain 25% increased resistance against Toxins and Poison. This is a pretty average upgrade, as you can simply use a Hazard Suit to fix anything that might affect you.
- Pharmo-Friendly: Efficiency of Hypos is increased by 20% and it’s one of the best ones to choose since it affects your healing stats.
- Pack-Rat: You gain three additional inventory slots for this upgrade. It’s not that useful since increasing your Strength lets you carry more items anyway.
- Speedy: You receive a 15% increase in movement speed from this upgrade. This is also a very bad one since you can simply increase your Agility once or twice.
- Sharpshooter: Your ranged weapons will receive a 15% damage increase. This is very good since it will help take down enemies faster and conserve ammo.
- Cybernetically Enhanced: You can use two Implants at once. This is extremely good since Implants massively enhance your character, and it will come in handy both in the early as well as endgame.
- Tank: Your HP is increased by 5 with this upgrade. It’s also not very good since you can increase your Endurance and get way better returns.
- Lethal Weapons: This upgrade provides a 35% boost to your hand-to-hand damage. If you’re looking for a melee gameplay with your Wrench, this is a must-have upgrade for you.
- Security Expert: You receive a +2 boost to Hacking when trying to hack Security Control Stations. One of the worst skills you can pick up since upgrading your Hack skill gives way more value.
- Smasher: This upgrade allows you to land a powerful overhead attack when using a melee weapon. It’s a potent skill, but only valuable if you’re going for a melee build.
- Cyber Assimilation: Extracting Repair Modules from robots will restore 15 HP. This ain’t good either since healing items are quite abundant in the game.
- Replicator Expert: Your Replicator purchases will have a 20% discount. This is also a good upgrade to choose, as Replicators offer valuable items, and buying them for a low price makes your journey easier.
- Power Psi: You don’t take damage when affected by Psi Burnout. While it’s good, it’s only valuable if you’re playing a Psi character and looking to unlock endgame spells.
- Tinker: You receive a 50% discount when upgrading weapons. This is also a pretty average skill to unlock since you won’t be upgrading every weapon in the game.
- Spatially Aware: Upgrade locations are automatically revealed. This is also not very useful, especially if you’re someone who frequently explores the Von Braun and the Rickenbacker.