In the table-top wargame Warhammer 40,000, the Necrons are a mysterious race of skeletal warriors that have lain dormant in their stasis-tombs for millions of years. They are ancient beyond reckoning, pre-dating even the Eldar. Yet, they are beginning to awaken, for the galaxy is ripe for harvest.

The Necrons' story is one of an ancient betrayal. Aeons ago, the Necrontyr race clung to their short lives in fear of oblivion at the hands of their massive and ravaging star. They pushed the limits of science in an effort to lengthen their lives, but to no avail. Then, the star gods known as the C'tan were discovered, offering immortality at a terrible price.

The C'tan are huge energy beings who were given physical embodiments by the Necrontyr, originally there was a large amount of C'tan the four most noticeable are The Night Bringer, The Deceiver, The Void Dragon and The Outsider.

The Necrontyr agreed, and their souls were encased in living metal bodies. What they did not know was that the process dulled their minds and senses so they became slaves of the C'tan. The C'tan needed warrior-slaves to harvest the lifeforms of the galaxy so the star gods can feast on souls, and the C'tan's new Necrons served this purpose well.

After life across the galaxy ran thin millions of years ago, the Necrons went into stasis, waiting for life to grow back. Now, in the 41st millennium, they have found a galaxy teeming with life again.

In combat, the Necrons are unyielding war-machines that bring swift death to their prey. Armed with Gauss weapons that strip an opponent's molecules one layer at a time, the Necrons have fierce firepower. Also, the Necrons have a remarkable ablility to repair themselves, a Special Rule known as "We'll Be Back!". This gives the Necrons incredible staying power in a battle, which makes them an enemy dreaded by all races in the world of Warhammer 40,000.

The Necrons are heavily reminiscent of the cyborgs in The Terminator films, as evidenced by the machine-like qualities, the shared skeletal appearance and the "We'll Be Back!" rule, a play on Arnold Schwarzenegger's signature line: "I'll be back". The Necrons are also possible opposites of the Warhammer Fantasy Tomb Kings army. Their background also has many similarities to the Cthulhu mythos, with tales of ancient, manevolent gods awaking after eons of slumber to plunge the universe into neverending darkness.