Every Dalek in Doctor Who, Explained
Doctor Who's Daleks have undergone several upgrades since their debut in the 1960s, and each model in the show presents a new challenge for the Time Lord.

Doctor Who's Daleks have undergone many changes since the 1960s, with each new type differentiating them from previous generations. In addition to the aesthetic changes to their armored bodies, the Daleks have seen quite a few ability upgrades, making them even more efficient extermination machines. Their ability to upgrade themselves made them Doctor Who's most memorable villains, and even after a long hiatus between seasons, the Daleks eventually returned to continue haunting the last Time Lord.
First appearing in the 1963 TV series The Daleks, the inhabitants of Skaros have been a part of Doctor Who lore from the very beginning, and remain an important part of that lore today. Many of their early changes were out of necessity, but Doctor Who continues to tease the new Dalek design, even if the BBC isn't as technically constrained as it was when the show first ran. No matter how many upgrades and design changes the Daleks go through, their look will always have a touch of early '60s glamour, and they've moved beyond Doctor Who to become a sci-fi fixture Pop Culture.
Mark 1

Physically, the Daleks of the TV series Daleks are not much different from their modern image, but their limitations in the story compared to today's killing machines make them almost comical. They have the iconic pistons, barrels, and bulbous eyestalks, but their bases are much larger than those that came later, and they're noticeably less mobile. Their power comes from static electricity on the metal floor, and this history of Daleks origin hinders their development until the second generation ignores this problem. The original Daleks were important because they introduced legendary characters, but it was clear that a change needed to be made.
Mark 2

In 1964, the Dalek Invasion of Earth introduced fans to a better-known version of the Dalek, who received a mobility upgrade that allowed them to roam freely while filming on location. The second-generation Dalek has a larger bumper to hide its wheels, and a small satellite dish that allows the unit to receive power remotely. The rest of the body is largely unchanged from when it first appeared, the only upgrades are because the story requires them. Re-detect static electricity problems may have It's confusing to Doctor Who's continuity, but it's the smartest way to move the Daleks' more powerful villains forward.
Mark 3

The third generation of Daleks is really where Galactic Destroyer hits his stride, and many of the changes made to the design and powerplant since the original Doctor Who run are reflected in the character. Debuting in The Chase in 1965, the Mark 3 Dalek had a smaller bumper, similar to the Mark 1 design, with metal braces around the midsection replaced by vertical slats, giving them a cleaner and cohesive look. First seen in color in 1972's Day of the Daleks series, the Mark 3 unit appears in a drab gray with a tinge of military efficiency.
The legend of the race was further fleshed out throughout the 1970s and 1980s, and while the full timeline of the Dalek was always vague, many important pieces of continuity were established during those 16 years. Apocalypse of the Daleks, from 1985, introduces the Imperial Daleks, a subset of the race created by Davros, equipped with an off-white paint scheme. Likewise, the imposing special weapon Dalek introduced in 1988 Memorial to the Daleks, a tank-like subset equipped with a massive cannon and a shanty dome. Remembrance of the Dalek also adds an important new ability to the Imperial Dalek's arsenal, as they are proven capable of flight.
Dalek Hierarchy

Most of the Daleks in Doctor Who are just drones and soldiers, but the show occasionally glimpses the upper echelons of Skaros society through Emperors and Supremes. For years, Doctor Who has made it clear that the Daleks are the bad guys, but their physical limitations were exemplified when they first appeared in the 1967 series "The Evil of the Daleks." Originally depicted as a man fastened to dozens of wires and pipes, the emperor could only really call the shots. Subsequent redesigns have made the leader more visually interesting, but his limitations continue.
Supreme Daleks are more maneuverable and, apart from some aesthetic differences, are very similar to the drones they command. Making his debut in 1964's The Dalek Invasion of Earth, Supreme, then known as Black Dalek, only had a dark paint job to set him apart. During Doctor Who's Mark 3 era, the show's extra Dalek Mutants revolutionized the franchise and proved that the ever-changing state of its hierarchy kept each appearance fresh and exciting. By the modern Doctor Who era, Supreme Dalek had a new look, including a red body and array of prominent metal necks, as seen in the 2008 episode "Stolen Earth".
Time War Daleks

The time war between the original Doctor Who and the revived series changed the course of the show's universe, and the Daleks didn't miss an opportunity to get in on the action. Already a warlike race, at first the Age of War Dalekhs shed any aesthetic pretense and went into battle with bronzed bodies reminiscent of the dull bombers of many wars on Earth. The 2005 episode "Dalek" explains that the races almost succeeded in winning the conflict, while many mysteries about the time wars remain in the Doctor Who continuity.
New Paradigm Daleks

After the reappearance of the Time War Daleks nearly made the Doctor dizzy in "Dalek", the Doctor Who revival finally reworks the Dalek in the form of a new paradigm. After a disastrous defeat in the Time War, the Daleks Enter the universe to preserve their genetic purity and reform the Empire to a new paradigm. In the 2010 episode "Victory of the Daleks", this restructuring was accompanied by a new shell design. New Paradigm Daleks are taller and bulkier than their predecessors, and a color-coding system was added to their hierarchy, with each class represented by a specific paint scheme.