Items

Items are objects sold by shops or dropped from Roshan that provide an ability, bonus, or other function not tied to a particular Hero (the only exception being Aghanim's Scepter, which changes certain Hero abilities). They come in a multitude of forms and types, and as such can be very different from one item to the next.

Items take up space in a Hero's Inventory, meaning only six can be carried at one time. If a hero buys another item while their inventory is full, it will automatically go to their stash - which can also hold six items. If a hero buys an item with both their inventory and their stash full, the item will be dropped on the ground in their fountain.

Recipe items will automatically remove their components from a Hero's Inventory and Stash when they are assembled. Because of this, strategy and thought is required in the order and selection of items to purchase.

Heroes can use most of the available items, but some items will provide no effect or cannot be purchased by some Heroes. For example, most heroes with a bash ability cannot purchase Skull Basher.

Heroes cannot use items purchased by other heroes, with a handful of exceptions. See Item Sharing for details. In addition, some items can be disassembled. See Disassemble for details.

Most items may be sold back to vendors for 100% of the gold spent either within 10 seconds after purchasing or until the item's active ability (if it has one) was used the first time. After ten seconds have passed items may be sold back for only 50% of its price tag. Some items cannot be sold, for example, Gem of True Sight, and for some Heroes, Aghanim's Scepter.

Gameplay
Purchasing items is essential to the course of the game, as items provide necessary benefits that improve the effectiveness of both Heroes and their team. Heroes without items, or with poor item choices, suffer greatly compared to Heroes with items that synergise well with them.

Items provide addition benefits to Heroes that levelling up cannot. These include attribute bonuses, additional movement speed, auras, active abilities, and passive effects that aren't included in the Hero's innate abilities. Because of this, a Hero will want good items in order to improve the effectiveness of their team.

Item choices, the amount of items, and the speed at which items are obtained determine how effective a Hero's team can be. A support Hero wouldn't want to spend too much money on damage-dealing items, because they don't benefit as much from it as a carry would. A carry hero would want to gain as much gold as they can in order to buy better items than their enemies, which is why farming is important to carries.

The amount of items a hero needs to be effective varies greatly depending on role. A support hero doesn't need many items at all to be effective, which is why they often buy support items like like Observer Wards. A semi-carry or initiator only needs one or two items to be effective, such as a Blink Dagger or Aghanim's Scepter. A hard carry requires many powerful, expensive items to reach their potential - and as such gain the most benefit from items.

Trivia

 * You can buy items, sell items, and access your stash from the shop located at the enemy fountain without being within the fountain attack radius.
 * There are 47 basic items, 12 secret shop items, and 70 items that can be assembled by combining other items - which makes a sum of 129 unique purchasable items (excluding Roshan drops and seasonal items).
 * You can destroy dropped items by force-attacking them, including Aegis of the Immortal and Cheese.
 * You cannot destroy allied items, unless they are sharable.
 * You can destroy enemy items if they have been dropped.
 * The items that you can never destroy are Gem of True Sight and Divine Rapier, even if you owned them.