Sympathy is the science of converting between multiple forms of energy though force of will ("Alar"). This changing is done through any one of ninety bindings (and potentially several dozen advanced bindings), such as "Motion to Light" or "Parallel Motion". A binding is cast through muttering the words and focusing. It is extremely difficult for a sympathist to maintain multiple bindings, as the mind must be split to maintain them; Kvothe can manage six, and Devi can manage eight. Sympathists may use a focus, such as pine sap  or a piece of metal , to help them concentrate and perform the bindings.
The laws of sympathy are as follows :
- Correspondance: Similarity enhances sympathy.
- Consanguinuity: A piece of a thing can represent the whole of a thing.
- Conservation: Energy cannot be destroyed nor created.
The less similar two objects are, the harder it is to perform and sustain the binding.
- The words of the sympathetic bindings are never said in the book.