General upgrades are upgrades that are provided by the collector for a certain amount of cells. You mostly need a certain number of unlocked items to be able to get these upgrades but only for some do you need a blueprint. Below is a list of what you can upgrade to make your runs overall better.
(1.6; flask 3 and 4, gold reserves 3,4 and 5 and theadvanged forge cost less cells)
The amount one can heal, max 4 flasks at the same time The requirement for these upgrades is that the player already has the previous upgrade of the flask and 10/25 unlocked items for the 3rd and 4th flask respectively (for the 1st and 2nd no other unlocks needed).
A health flask heals 60% and reduces malaise by 5 bars under normal conditions (no mutations etc.)
Again one does need the previous upgrade to get the next one. Up to 5 levels where the bag holds 3.000/6.000/10.000/15.000/25.000 gold respectively when the player dies or completes a run.
For the first bag you need to have health flask one. For the 3rd,4th and 5th bag you need 8/15/30 unlocked items.
The fifth bag also requires the player to have completed the game at least once to find the blueprint in the ancient sewers.
Recycling (1 and 2)
Items can be recycled for gold (7% and 15%) based on the selling price in stores.
1 Flask required to unlock recycling.
Random Starting Gear
Gives you a random melee/ranged/shield at the start of a run of the ones you have unlocked.
The real starting gear like “rusty weapon” can be found below the platform with the axe (where you respawn) for the achievement that requires you to complete a run with one of those.
For the shield and bow upgrade you need 2 unlocked items for the sword you need 12.
Makes it able to refresh a store (does not apply on food shops). You need to unlock 20 items to get this upgrade. (You can refresh twice).
Unlocks the specialist shop in the beginning area with the Hunter’s grenade the forgotten map and the Golden outfit. Makes your search for blueprints easier… at a price. You need to unlock 20 items to get this upgrade. (on the end is always a warp-point)
Unlocks a mirror between the door to the daily challenge and The Scribe (the NPC who records your achievements) which shows you an enemy/boss who has a blueprint that you don’t have (yet). It can show enemies that you don’t have access to yet (like the giant before you have access to the cavern) and it does not specify which difficulty. You need to have specialist’s showroom unlocked to get this at The Collector.
You can choose what a shop sells (does not apply to food shops). You either have the choice between Turrets (and other deployments)/Grenades/Powers (skill-shop) or Melee/Range/Shields (weapon-shop). Helps you know item pools better and you have more chance on gear that is useful to you.
You need to have 30 items unlocked to get this upgrade. This upgrade has a blueprint that is located in the graveyard behind a locked door which requires a hidden key.
Blueprint found by beating the hand of the king in 1BC (need to beat 1 BC). You get four tubes with each a melee weapon, ranged weapon, shield and two skills at the beginning of your run. You can only choose one set.
The Legendary Forge
The forge is an upgrade from the collector which requires 40 unlocked items and to have Gold reserves IV (bag 4).
The forge can be found behind each boss fight where the blacksmith offers you to spend cells so the quality of gear that you encounter becomes better.
You can’t max the forge bars to the fullest until you reach certain difficulties.
The total amount needed to get all bars full is 10.000 cells.
With a fully maxed forge 100% of the gear you encounter will be S-tier. This gear cannot be upgraded but the affixes can still be reset. Weapon-tiers will be the max unlocked level even if you go back to 0 BC. (so still 100% S-tier)