Items in UnderMine can be categorized into two distinct groups: permanent items that persist after death, and non-permanent items that are lost upon death. Items can progress the game's storyline, confer special effects, or offer statistical bonuses. Certain items will be Automatically Unlocked at the start of a new game.
Permanent items
Artifacts
Artifacts are story-related, or "key", items in UnderMine. Their discovery progresses the game's storyline in a certain way, like unlocking certain NPC shopkeepers in the Hub. They are not lost on death.
Equipment upgrades
Equipment upgrades are persistent items that are purchased from NPCs. These items govern the player's five basic stats: Max Health, Swing Damage, Throw Damage, Bomb Damage, and Gold Integrity. Apart from these, one upgrade increases the throw distance of your pickaxe. These items are reflected under the Peasant tab in the Journal.
Non-permanent items
Basic Items
Basic items, like bombs, and keys, are picked up while adventuring or purchased in the Hub or a Shop.
Food
Food is a category of consumable items that restore a certain amount of hp to the peasant when you collect them by running over them. The only real difference between food varieties, if any, is exactly how much hp is restored by collecting them.
Relics
Relics are items that confer special bonuses or effects. There is no limit to the amount of relics that the player may carry. However, all carried relics are lost upon death. Relics are either found while adventuring, bought in the Shop, or crafted by Wayland in the Hub.
Potions
Potions are consumable items that confer special bonuses or effects. Like relics, potions can be discovered while adventuring, purchased in the Shop, or crafted by Baba the Alchemist. At first, only one potion may be carried at any given time, but the number of potions that can be carried can be increased by purchasing special items.
Blessings
Blessings are buffs which positively affect the player in many different ways, such as granting bonuses. They can be obtained from Altars, killing Hoarding Pilfer, opening Chests, or at the beginning of any run if the player has any 
Censer items.
Curses
Curses are debuffs which negatively affect the player. They can be obtained from Altars, blowing up cursed flames, buying items for curses, using levers which give curses, opening Cursed Chests, or from 
Will o' the Wisp.