Dalek hierarchy

Due to their highly militaristic culture, the Daleks operate under what is nominally a rigid hierarchy; there are often variations to it, however, depending on era and circumstance.

Figurehead

 * Dalek Emperor - the overall leader of the Dalek Empire.
 * Davros - the creator of the Daleks who served as leader of the Imperial Daleks.
 * The Mentor - the creator and leader of a faction of Daleks from another universe.
 * Dalek Supreme - a white Dalek leading the restored faction.

Council

 * Cult of Skaro - A council of elite Daleks created to think of imaginative strategies, previous to or during the Last Great Time War (DW: Doomsday onwards)
 * Dalek Council - A governing body under the Emperor. (REF: Doctor Who: Aliens and Enemies) In some instances, they appear to rule the Daleks in the permanent or temporary absence of an Emperor. (DW: The Daleks, Planet of the Daleks)
 * Emperor's Personal Guard

Commanders

 * Dalek Supreme - High-ranking generals, commanding major operations or planetary occupations. These are usually black. In the early days of the Daleks, the Supreme was the direct second-in-command to the Emperor. (The Dalek Chronicles) During the Imperial-Renegade Dalek Civil War, the Renegade Dalek faction was led by a Supreme instead of an Emperor; and in the New Dalek Empire, a Supreme Dalek took command. (DW: The Stolen Earth)
 * Dalek Supreme Controller - Red-coloured Daleks, second to the Supreme. (BFDE: "Death to the Daleks!")
 * Dalek Scientific Division - high-ranking, their needs override all other orders and concerns. (BFA: Return of the Daleks) Science Daleks have been claimed to be silver. (The Dalek Tapes)
 * Dalek Saucer Commander
 * Blue Dalek - equivalent of non-commissioned officers (EDA: War of the Daleks)

Low Ranking Daleks

 * Standard Dalek
 * Special Weapons Dalek - designed solely for combat, lacking the abilities of the standard Dalek.
 * Marsh Dalek - designed solely for swamp combat.
 * Spider Dalek
 * Marine Dalek
 * Dalek-Humans - Humans altered with the Dalek Factor or Dalek DNA

Non-Daleks - Servants, Mercenaries and Slaves

 * Humans and Near-Humans - slaves and mercenaries, includes:
 * Robomen - slaves under heavy mind control
 * Dalek Troopers - mercenaries, initially (DW: Resurrection of the Daleks)


 * Robots - servants, includes:
 * Robot Dr Who - a robotic duplicate sent to kill the original (DW: The Chase)
 * Movellans - robotic servants (according to EDA: War of the Daleks)
 * Edwin Bracewell - human android (DW: Victory of the Daleks)


 * Ogrons - mercenaries
 * Exxilons - slaves (DW: Death to the Daleks)
 * Werelox - mercenaries (DWM: The Dogs of Doom)
 * The Mighty Jagrafess of the Holy Hadrojassic Maxarodenfoe, itself served by the Editor. (DW: The Long Game)
 * Pig slaves - slaves (DW: Daleks in Manhattan/Evolution of the Daleks)

Visual distinctions
Daleks often showed their rank via colours. In one version, gold Daleks are the highest, followed by black, red, blue and grey. (EDA: War of the Daleks) The Dalek Tapes, a feature in the Genesis of the Daleks DVD, has golden Daleks as members of the Supreme Council, followed in rank by black (Dalek Supreme), partially black, silver (scientific corps), and grey.

For a time, the majority of Daleks were silvery with blue "bumps", with Saucer Commanders being partially black and Black Daleks/Dalek Supremes being full commanders. (DW: The Dalek Invasion of Earth)

During the Last Great Time War and in the New Dalek Empire, almost the entirety of Daleks shown were of the same colour; the Supreme Dalek in the latter was marked out by being red, while Dalek Sec of the Cult of Skaro was black.

The restored Daleks sported bright colours, with each colouring showing their role: the Supreme was white, the strategist was orange, the scientest was blue, the drones or soldiers were red. A final yellow Dalek with black globes (as opposed to the silver utilised on the other four types) was the mysteriously named "Eternal". (DW: Victory of the Daleks, Doctor Who Confidential)

Purity
Daleks ranks have often been established by their genetic purity. In Parting of the Ways, the Dalek Emperor created his new army out of Human DNA, which caused them to not only obey but worship the Emporer as the only pure Dalek.

When the new Dalek Race was created from pure Dalek DNA found in the progenitor (DW: Victory of the Daleks) both them and the impure Daleks which created them believed the new race were superior due to their purity, and that any impure forms must be destroyed.