Path of Exile Item Upgrading
Players can upgrade their weapons and equipment using new accessories. They can also increase its stats base or add additional benefits. To upgrade an item, a player has to have it in their inventory and have access to the kiln.
Usually items that have weak bases (like rings) can be upgraded to a more powerful base while items with strong bases like eth titans do not vary significantly in their stats after being upgraded.

Upgrade components
Upgrade components can be used to upgrade weapons, armor, trinkets and gathering tools, giving an attribute bonus or additional effect when the equipment is used. They can be purchased from vendors, or found in loot, dropped by enemies, or obtained as rewards from missions or chests. Some upgrades have additional cosmetic effects. Most upgrades require that the equipment be at a certain level before you can upgrade.
In order to upgrade the quality of a weapon or piece armor, the player must select it and then click on the Upgrade button in the toolbar. This will show on the right-hand side of the screen a preview showing the expected upgrade statistics and the necessary component or materials.
There are three types of upgrade components including universal upgrades, prefix upgrades, and suffix upgrades. Universal upgrades, which comprise gems, can be put in any type of equipment, and offer lower bonuses than upgrade components that are type-restricted. Infusions are jewels that are only available in equipment that is legendary or ascended. They provide the same benefits as jewels, but cannot be used in other equipment. Suffix upgrades can be added to gathering tools. They add the suffix at the end of the item's name. For example adding the suffix Glyph would make the staff wrapping of Minor Vigor into a Canthan staff wrapping of Minor Vigor.
In the instance of upgrades for gathering tools, if a player replaces one glyph with another the previous glyph will be returned to the inventory. If you replace another upgrade component the item will be destroyed, except for inscriptions, which can be freely swapped.
Leveling
Path of Exile's upgrade process is different from the previous versions in a few important ways. Gear is now broken down into tracks and items can only be upgraded a specific number of times before they're "leveled out." The cost of upgrading increases with each level, however the materials required for upgrades do not. This allows players to concentrate their efforts on a few important items to maximize their impact instead of spreading upgrade costs across several items.
This will enable the item to receive upgraded components and a greater chance of success. This bonus is referred to as the Artisan's Energy and it will reset to zero in the event of failure, or increases when the upgrade is successful.
When a piece of equipment is upgraded to its highest level it is able to gain affixes which will enhance its capabilities. The amount of affixes available is determined by the item's class. For instance the rare or exclusive weapon with a base that is normal will have only two affixes available for it, while legendary armors will have up to eight affixes for it.
Each upgrade requires a certain number of Flightstones and crests to complete, depending on the item's current level and the item slot it's in. Weapons will typically require more Flightstones than other equipment.
If an item fails to attain its maximum level, the NPC gives the player the choice to transfer it to a new character and then re-infuse it with a different set of upgrades. This process can take between one and two hours and will cost the same amount of material. However it has a lower chance of success.
Engineers employ a level to measure the height of the building to a known point, such as a benchmark. This is referred to as a "level-loop." It involves taking readings with the level, backsighting rod, and then turning the level to take the foresighting rod reading. This method ensures that buildings are built to a high level of accuracy and safety.
Rerolling
Rerolling is the process of changing the upgrade components of an item. It is a vital aspect of the game and can significantly increase the strength of an item or damage, as well as other attributes. This can be done through the item menu or pressing the Reroll button of an upgraded item. Rerolling is costly and should only be performed in rare cases.
Reroll tokens are earned by recycling upgraded items. These tokens can be used to upgrade the original item or another similar item. Recyclable items have an indicator of level that indicates how much of the upgrade gauge is filled. The amount of level that has been filled is contingent on the rarity and the upgrade cost of the item.
Prior to this, some upgrades were given priority affixes which made them easier to roll. This meant that you could receive the stats that mattered most to your build often than other. These included things like the armor's total armor, thorns and duration reduction statistics that were controlled or the weapon's bonus attack speed and critical strike chance.
This has changed since the last patch. Priority affixes have been removed, and all upgrades have the same chance of rolling for each stat. This can be either good or bad, based on what you're looking for and want from your equipment.
Each upgraded item may come with a bonus that increases the power of the item by a fixed percentage or a flat amount. These bonuses are added to standard affixes. The more you improve a product, the higher the chance of receiving an exclusive bonus.
The game also includes various sets that offer a set-based bonus when three or more upgraded items from the same set are installed on an item. This is a great way to give an individual character more power without spending a ton of money.
Many players prefer to reroll their equipment and weapons, especially in the beginning of the game. Rerolling is a way to create a more powerful character faster, allowing players to advance in the game and attain higher tiers.
Sets
Sets are collections of elements that can be arranged in a variety of ways. They can be different dimensions, have none of the elements, or contain a single element. They can be used to organize data or organize information. They can also be used to study patterns. Sets can be classified in various ways such as size and shape.
The Legend of Zelda Tears of the Kingdom offers a wide range of set items that can be upgraded. Certain items are worth upgrading while others aren't. Upgrades are worthwhile for armor sets that provide high defense value and set bonuses. However, most upgrades to weapons don't improve the quality of the item's stats when as compared to their purple counterparts. This makes them less appealing to upgrade in the event that your collection of armor and weapons pieces is already extensive.
Certain set items are upgraded to meet their own special functions, which can be particularly useful in certain builds. This is evident in Aldur's Advance Boots and Guillaume's Face. Both were upgraded to Exceptional Winged Helms and Exceptional Mirrored Boots, respectively. This increased their defense from 217 to 321. (Strength requirements and Level requirements were also increased).
Another reason to upgrade certain items is to bring them into parity with their levels. For instance the Immortal King set has a vast range of levels, ranging between 29 and 76. Upgrades to lower-level items could improve their defense, and increase their competitiveness in terms of damage.
Clicking item upgrade will display the item's attributes and the necessary items needed to upgrade it. This will display the item's attributes, along with the required items to upgrade it. To upgrade the No-mouth face, for example, 1.1K Scrap Materials will be required, along with 250 Enchanted Dust and 5 Glowing Shards. Alternatively, players can visit the Leaderboard or Golden vendor in Cyrodiil to see the upgrade requirements of specific items.
In general, armor and weapons have a higher trade value when they are updated. Upgrades to gold are recommended for weapons that have spell/weapon-damage glyphs. This will bring about a significant improvement in their stats. Weapons with an upgraded appearance will benefit from this upgrade because its defense will increase as it moves from purple to gold.