The djinn - whether they like it or not - are the guardians of luck, so they derive their power from "luck" or "fate". Much of the narrative thus comes from those who promote good luck, who are attempting to combat those who promote bad luck. In particular the book focuses on the Marid, led by Layla Gaunt (John and Philippa's mother), a tribe of djinn, to which the Gaunt family belongs, and the Ifrit, led by the evil djinn Iblis, who provide many of the enemies in the five books. With the book's logic, they do not consider it magic, but a force from an undefined section of their brains.
The djinn power that all djinn possess is directly linked to their own lifelines, every wish that is granted costs the djinn a portion of their lifeforce and shortens their lifespan. The energy that is lost cannot be regained and the older a djinn is, the more force is drained from them. Djinn require heat to use djinn power. The younger a djinn, the more heat required to use djinn power. An adult djinn must be frozen in ice to prevent use of djinn power. The average temperature of a healthy djinn is 101.6 degrees Fahrenheit. Djinn shake hands by folding their middle finger or their "life line" finger into their palm to protect it from other djinn who may want to use their powers
The exact limits of djinn power vary with age and experience, but what all djinn have in common is that when they use their power they must picture and think about what exactly they will use their power for be it from making an object appear and disappear to granting a wish. Djinn power has limits, as stated by John and Philippa's mother that djinn cannot bring back the dead be it animal, human, or plant. Djinn power cannot effect the flow of time and cannot create copies of themselves. Also, djinn cannot undo the spells of another djinn, except the Blue Djinn of Babylon. Djinn power cannot create gems of any kind because gems act like absorbers and take in djinn power.
Djinn power allows djinn to grant three wishes per individual, also there is a fourth wish in the event the individual does not like the outcome of the wishes and can unwish the previous three. Also, it has been proven that djinn can offer three wishes to anybody; instead of having to be released from a confinement every time to bestow the wishes' to individuals, if djinn are released from a bottle by a member of their family, then no wishes would be exchanged. Djinn can also give another djinn or human an emergency wish called a discrimen; that allows them to avoid any kind of danger, usually the emergency wish is a very long word and the person can only remember and say it right in the event an emergency occurs, however two discrimen's would cancel each other out when activated. In the 2nd book, it is shown that a creature called a optabellower or wish monster was spawned from the 1st Blue Djinn's mind from which it was created from the angry and thrown away wishes of mundane and djinn.
When djinn power is released there is a surge of energy that effects the djinns surroundings; for example, before John had his wisdom teeth removed his untapped djinn power caused a crack to stretch from his bedside to his side of his bedroom, through a mirror and ended just a few feet from the bedroom door.
It also appears djinn age slower than mundanes, because according to Nimrod djinn can live up to 500 years and if bottled up in suspended animation, time cannot ravage a djinn until released from the bottle. In fact, djinn do not actually start aging until their wisdom teeth are taken out no matter how old he/she was before the wisdom teeth were removed.
Djinn power allows djinn to have an astral body, that allows them to enter other people's dreams and gives them access to possess people. Plus, if their physical body gets destroyed, their astral form can enter into any human spirit and in turn, the host becomes the djinn's new body still retaining all the djinn's knowledge and personality. The dangers involved in using the astral form is that the ghostly form cannot stay out of a body too long or it floats into space becoming a lost spirit. Plus, the spirit djinn can still be heard by other beings be they mundane or djinn, the spirit must avoid being exposed to cold air because the cold air will affect their astral form and make them semi-transparent enough to see. When a djinn possess someone, the host maintains his or her original appearance and voice. While under possession, the host has no memory of whatever occurred while they were being possessed. The way to tell is someone is being possessed by a djinn is if there is a smell of sulfur in the air and if the lymph nodes in the throat is swollen than a djinn is present, a djinn's spirit can be exorcised by the burning smell of cat.
Djinn have the power of shape-shifting and can change into any animal or object the choose. While in animal or object form, the djinn still retain their thoughts and 5 senses granting them a form of telepathy to communicate to other djinn while in an animal or object guise. The downside to shape-shifting into an animal is that the djinn retain some animal-like qualities when they change back into their mundane forms; such as the animal's scent, plus they can only stay in animal form for a limited time. An exception to the time limit is when the djinn change into their tribe's special animal; for example, the camel is regarded as the animal of the Marid tribe; therefore, djinn of the Marid tribe can stay in camel form for an indefinite amount of time. When djinn are disguised as objects such as walls or statues they must act like objects, that is to be seen and not heard.
Djinn have the ability to turn into smoke when they enter or exit a container, called transubstantiation. This process occurs when the heat from a djinn body's ignites with the oxygen in the air giving the illusion of smoke,. When a djinn enters a container they must enter counter-clockwise if they are in the northern hemisphere; because when they enter the container time is different for they step outside the third dimension. Space in a bottle to a djinn is very much like a room in a house for which they still retain djinn power and are able to make their stay comfortable for themselves. Because djinn are outside the third dimension time is different inside the bottle, to a djinn an hour in a bottle is similar to ten hours outside the bottle. However, if a djinn enters the container the wrong way the opposite effect happens, in which 15 minutes outside the bottle may feel like three days in the bottle.
Because djinn are made of fire, smoking is not an uncommon habit for them because the negative effects of smoking do not affect them and as Uncle Nimrod has demonstrated, can change the smoke into many different shapes. When djinn enter a container they can survive the low oxygen confinements in the container while a normal mundane would choke to death on carbon dioxide. It has also been shown that if a human injects djinn blood into their system they will suffer spontaneous combustion and be reduced to ash. It has also been confirmed that djinn are immune to fire and can not be burnt or killed by it.
Djinn can unleash an elemental on another being, elementals are mini-demons that live inside what djinn call the eight elements: water, earth, fire, air, spirit, space, time, and luck. Elementals tend to follow their creators once they carried out the deed they were created for and often help out their creator in times of crises. Dybbuk once released one by holding hands with the Gaunt kids.
Djinn have the ability to travel by whirlwind by means of forming a funnel of air for which they must sit on or risk of losing balance and falling off. Just like inside a bottle, djinn can adjust the inside of the funnel to their liking and mundanes can travel with them inside the whirlwind. However, djinn must make sure that mundanes do not see the whirlwind for risk of exposure and whirlwind travel is sensitive to changes in the Earth's temperature.