Insert Sockets to Equipment
Equipment sockets can be embedded with runes. Each socket can be embedded with one rune.
Each equipment allows 4 sockets at most. Total number of sockets = number of natural sockets + inserted sockets. A piece of equipment may have 0-2 natural sockets and a maximum of 2 inserted sockets.
Sockets on the equipment that you get from monster hunting or purchase from the stores are called "natural sockets". Since only two natural sockets at most are allowed, so if you wanna have a piece of equipment with 4 sockets, you have to obtain the equipment which already has 2 natural sockets first, and then insert another two sockets on it.
How to insert sockets?
Go to a weapon store in any town to do it. 20 Dragon Gold should be paid for inserting the first socket to the equipment, while the second socket will cost you 50 Dragon Gold.
Monsters have certain chance to drop different levels of runes which can be embedded into socketed equipment. Each socket can be embedded with one rune.
When a rune is embedded into the equipment, it will enchant the equipment with the effect of the rune. For example, when Water Strike rune is embedded into a weapon, the weapon's Water damage will be increased.
How do I embed a rune into the equipment?
Simply click "Upgrade" on the character stats panel on the left to enter the "Embed" interface.
After you refine, combine or insert socket to the equipment that is 10+ levels above yours, the equipment will be bound to you.