Linking was a method of boosting the power of a spell by combining or linking the power of two or more gifted people. For a gifted person not of the House of Rahl to use the gift within the walls of the People's Palace, it was essential to link their powers so as to counteract the power spell there.
A notable example of linking webs occurred when Sister Ulicia and her band of Sisters of the Dark confronted Emperor Jagang for the first time. Ulicia, as the director of the Sister's combined strength unleashed enough power that she felt sure she could have ripped apart the fabric of reality. However, as Jagang was present within the Sisters minds she was unsuccessful.
Towards the end of the war, Sisters of the Dark Armina, Greta and Julia joined their gifts in an effort to combat the power spell over the People's Palace. This allowed the trio to murder Ann and capture Nicci. Following Nicci's rescue, Nathan joined his power with Prelate Verna Sauventreen and several of her Sisters of the Light in order to heal one of Nicci's rescuers, the sorceress Adie.