It modifies a Map item adding layers of Delirium with the
Gems reward type. Right click this item then left click a Map item to apply it. Can apply up to 5 to a single Map item. Shift click to unstack.
Active skill gems and support skill gems are usually referred to as skill gems. Skill gems must be equipped in item sockets before their use. Active skill gems grant an active skill for the player to use and are further augmented by linked support skill gems. There are currently 254 different active skill gems and 167 support skill gems in the game, for a total of 421.