The term 'High Rune'('HR' for short) is a term used by players on to refer to the most valuable runes. Upgrading to runes higher than Dol can only be done on closed B.Net with ladder characters, or by a single player character. Higher levels of runes can also be upgraded, but require an additional gem as well. El through Ort can all be upgraded similarly to gems by placing three of the same type in the cube and receiving one of a higher grade in return. Runes can be upgraded to higher runes through the Horadric Cube. The runes must be inserted in the correct order.Some runewords only work in weapons, while some only work in armors etc. If there are too many, the runeword will not work. The number of sockets in the item must be equivalent to the amount of sockets needed for the runeword.
Runes can also form runewords, powerful combinations of runes, if certain conditions are met: A rune in Diablo II is a small item which can be placed inside socketed items for bonuses to a wide array of different stats and abilities.
