The Necrons first appeared as usable units for Warhammer 40,000 as Necron Raiders. The rules for these were first published in White Dwarf Issue 216 towards the end of the lifespan of the second edition of Warhammer 40,000. At the time, only Necron Warriors and Scarabs were given game rules and the warriors were armed with Gauss-Flayer Guns. White Dwarf quickly followed up with an expanded army list in the following month's issue, number 217. The Necron Lord and Necron Destroyer were part of this slightly-expanded army list. At the time, the lord was armed with the Staff of Light while the destroyers were armed with Gauss-Cannons. This issue of White Dwarf also had the Necrons' first major appearance in a battle report in the article entitled Massacre at Sanctuary 101, a battle between the Necrons and the Sisters of Battle. This particular altercation soon made its way into the background material as one of the first times the Imperium officially encountered the Necrons. The first Necron miniatures, all metal, were also released during this time. In fact, a free Necron Warrior was included with issue 217 of White Dwarf.
In the release of the third edition of Warhammer 40,000 in 1998, the Necrons had no usable army list. The first, full-fledged Necron army list for the new edition of the game was printed in the March 1999 issue of White Dwarf, #230. This first army list was very restrictive, with the Necrons having mostly one choice per force organization category. The Necron Lord, Necron Immortals and Necron Warriors were the only available HQ, Elites and Troops choices respectively. This early army list had two units for the Fast Attack selections, Necron Destroyers and Scarabs. The latter were different from their current counterparts in that the original Scarabs were controlled individually and were not swarms on a single base as they are today. The Necron Immortal metal miniature was released at the same time as the publication of the army list. In a later issue of White Dwarf, Games Workshop further expanded the Necron army list by providing different equipment choices (wargear) for the Necron Lord. Along with the Gaze of Flame and Scourge of Light upgrades, this was the first time that the Veil of Darkness wargear was added to the Necron Lord's available options.
The Necrons received their first, full sourcebook with the release of Codex: Necrons in August 2002. The book featured a wealth of background information expanding upon the origins of the Necron race and expanded the scope of the Warhammer 40,000 history by several million years more. A full army list was also introduced in the sourcebook, with heavily revamped rules for existing units and the introduction of new ones. New units introduced in the codex were Flayed Ones, Pariahs, Wraiths, Heavy Destroyers, the Necron Monolith and the infamous C'tan. New miniatures were produced and released alongside with the release of the codex.
Necrons received their first plastic miniatures kit in the form of the Necron Warriors boxed set, which contained enough parts to make twelve Necron Warriors and three Scarab bases with four Scarabs each. The boxed set was a first for Games Workshop, as it was the first time that transparent, coloured parts were included in a boxed set along with the standard polystyrene parts. The transparent, green rods in this case were meant to be used as part of the Necrons' gauss weaponry. The Necron Destroyer model was also revamped and made into a plastic kit. Whereas the old, metal version was essentially a Necron Warrior riding a flying platform, the new Necron Destroyer plastic kit featured a Necron Immortal torso mounted and merged with a floating platform. The other miniatures released for the army were metal, such as the Flayed Ones, Immortals, Pariahs, Wraiths and the Necron Lord. Two more miniatures soon followed suit - the massive Necron Monolith, the largest miniature kit produced by Games Workshop at the time, and the Necron Destroyer Lord, a Necron Lord mounted on a Destroyer body.
On November 5th, 2011 the Necron line of models was updated with a new codex and many new models including sniper type Deathmasks and bodyguard type Lychguard. This new codex falls inline with most of the codex's that were released in 2010 and 2011, with a rich background and multiple independent character units with diverse abilities. The background of the Necrons changed radically in the new codex with the Necrons changing from mindless automatons to more freely thinking individuals capable of complex strategy and planning.