Runes cannot be bought from vendors in town unless another player sells them and at least one player remains in town afterwards to prevent the inventory being reset. The division between runes of low (El-Amn), medium (Sol-Um) and high (Mal-Zod) rarity is convenient rather than exact: for example, the Countess has a much higher chance of dropping runes than similar Unique or Super Unique monsters (up to an Ist Rune in Hell), while the reward for destroying Mephisto's Soulstone on the Hellforge is a much higher chance of a medium or high rune (1/11 chance each of a Mal Rune, Ist Rune or Gul Rune in Hell). Each rune fills one inventory space and they cannot be stacked. Monsters spawned in games with more players are normally less likely to have no drop and thus more likely to drop items (including runes), but Better Chance of Getting Magic Items has no effect on the quantity or quality of runes dropped. They can normally only be dropped by monsters, and their required level normally reflects their rarity (becoming rarer as rlvl increases).

Runes can also be used in combination to make Rune Words, as well as being required to make crafted items and make or manipulate other items using the Horadric Cube (including upgrading lower runes to higher runes). Once placed in a socket, a rune cannot be removed without destroying it. The bonus(es) added can vary depending on whether a rune is placed in a socket in a weapon, helm and body armor, or shield: Runes are small stones inscribed with runic characters which can be placed in any socket of an item to add bonuses to that item.

Diablo 2 lod rune list