Upgrade item

Most weapons/armors in FU can be upgraded (up to tier 10). Many tools (Mining Laser, Multi-ore Detector, etc.) are also upgradeable.

There are two methods:
 * 1) In your Personal Tricorder, you can upgrade weapon/armor (up to tier 6). This costs Upgrade Modules equal to the current tier of weapon: for example, upgrading tier 3 weapon to be tier 4 will require 3 modules.
 * 2) In your Personal Tricorder, you can upgrade tools (up to the maximum tier they support). This costs Manipulator Modules. Exact price is different for different tools.
 * 3) At the Cosmic Crucible, you can upgrade weapon/armor (up to tier 10). This costs Ancient Essence. When upgrading weapons, the Crucible will add a small bonus (on top of the stat increase that Tricorder could add) to various stats (damage, critical strike chance, etc.). Upgraded armors don't receive such bonus: they are exactly the same as if they were upgraded with a Tricorder.
 * 4) At the Cosmic Crucible, you can upgrade tools. This costs Ancient Essence.

Even tier 1 items are useful
After you upgrade it to tier N, a low-tier weapon/armor will have viable stats (on the same level as armors/weapons that were tier N to begin with). This allows you to use low-tier gear if you like its attack patterns (for weapons) and/or set bonuses (for armors).

Some low-tier items are incredibly strong when upgraded: for example, tier 2 Bone-Steel armor is famous for its high Physical Resistance at high tiers.

Unique upgrades
Some items turn into another (better) item when upgraded. For example, Bug Net turns into Superior Bug Net and Fusion Cannon turns into Blastmark.

Most items don't have a unique upgrade. They will receive increase of stats, but their name/image/icon will remain the same.