Created on the planet Skaro by the Kaled scientist Davros as engines of war and as the ultimate form of the Kaled race, the Daleks are undoubtedly the most evil creatures the Doctor has ever had to fight. They are utterly ruthless, calculatingly efficient creatures that are bent on dominating the universe: their might and technology are such that they instill fear into other intelligent species. Time is no longer a barrier to the Daleks, which can travel to a limited extent through time using taranium-powered machines.
Daleks are divided into two warring factions: the original Daleks that Davros created, now called Renegade Daleks because they turned on their creator, and the Imperial Daleks. Renegade Daleks have grey and black armour and are led by the Supreme Dalek, an abnormally intelligent mutant specially bred for the purposes of leadership. The Supreme Dalek is also known as the Black Dalek, because its armour is coloured black. Renegade Daleks seek only to exploit Davros's skills and do not acknowledge him as leader: to them he is only a resource of knowledge.
Imperial Daleks are the result of Davros's further experiments to breed infallible Daleks that are totally loyal to him. Imperial Daleks are a radical redesign with cybernetics grafted onto the mutants and are contained in upgraded cream and gold coloured armour casings capable of limited hovering ability, especially useful for overcoming obsticles such as stairs. Imperial Daleks are so radically altered from the original Dalek design that the Renegade faction no longer view them as Daleks. The Imperial and Renegade Daleks are dedicated to the extermination of each other and each will attack the other faction on sight.
A specially engineered Imperial Dalek with extra fire power, called the Special Weapons Dalek, is basically a Dalek tank. It is heavily armoured, has had its delicate bits removed, and a very large cannon added. The Special Weapons Dalek is called out whenever a battle is in danger of being lost. The appearance of a Special Weapons Dalek usually quickly turns the tide of battle in the favour of the Imperial Daleks. Due to the immense ammounts of radiation which the Special Weapons Daleks are subjected to, they tend to have damaged brains and are incapable of any independent thoughts other than those of killing and destruction.
Each Dalek faction is ruled by an Emperor Dalek. The Emperor of the Renegade Daleks has never been seen off Skaro and issues his orders directly to the Supreme Dalek. Eventually at some point in the future the Emperor Dalek became unable to leave his control chamber, standing immobile, linked into the Dalek network by cables. He thus became the Dalek nerve center. In order to expedite the conquest of the universe the Emperor decided to make the Daleks more cunning and deadly by intorducing 'The Human Factor' into their logical make-up. The plan failed with a civil war broke out between the Humanized Daleks and the original Daleks. In the ensuing battle, the Emperor appeared to be destroyed.
The Imperial Daleks are also led by an Emperor Dalek, which in reality is Davros in cream-coloured Dalek armour topped with a spherical case that hides his true form.
All Daleks have no benign emotions because Davros biogenetically engineered these weaknesses from their minds, leaving them only with strong emotions such as hate, revenge and cruelty. The weaknesses of the Daleks is that they are too logical and rely too heavily on their computers; they have lost the powers of intuition and inspiration.
Both factions use other species to compensate for their limited mobility. Ogrons are particularly favoured because they are stupid but loyal; human mercenaries are used reluctantly because they are by nature treacherous. The Daleks also enslave the populations of planets they conquer to provide work forces to exploit mineral resources, especially in dangerous environments.
Dalek armour is shaped like a pepper pot about 1.5 metres tall. The lower, slab-sided part is covered in large hemispherical nodules; its manipulator arm and blaster are connected to the mid section by ball-and-socket joints and may be replaced by other weapons and tools such as a cutting torch. A single eye-stalk juts out of its dome-shaped head. The Dalek creature itself is a hideous, green, multi-tentacled mutant about 60 centimetres across. It is as dangerous outside its protective shell as it is inside, owing to its incredible will to live and a murderous desire to kill.
Although Daleks are linked into a communication network, they also have the power of speech through a built-in electronic voice box. The harsh, grating voice box enunciates individual syllables: the word exterminate, for example, comes out as ex-ter-min-ate. Their conversation tends to be along the lines of: 'Exterminate', 'The Doctor is an enemy of the Daleks, he must be exterminated' and 'Halt or you will be exterminated'.
A Dalek's physical weak points are its eye-stalk and the manipulator arm. Attacks against these weak points only disable the respective part of the Dalek; they do not injure the creature inside. A Dalek with a disabled eye-stalk, for example, cannot see.
A virus developed by the Movellans specifically attacks Daleks. There is no known cure.
Daleks are supremely arrogant and overconfident; they often underestimate their enemies.