Excerpts from GURPS Egypt
Tomb Defenses (from the sidebar on pp. 95-96)
In early dynastic Egypt, people made their tombs accessible so that priests of the mortuary cult would have full access to their bodies – living warriors kept robbers away from the graves. As centuries passed, it became impossible for the cult to defend all the tombs of Egypt. Therefore, corpses began to be buried in places separate from the mortuary temples, and various mechanical and psychological measures were taken to protect the dead.
Most tomb defenses were rather simple. False tombs, sometimes equipped with small amounts of treasure so as to fool robbers, were built in accessible locations, while the actual tombs were in secret, wilderness places, their entrances blocked with enormous slabs of stone. The mortuary cult also propagated the idea that the ka of a dead person protected the grave, either as a ghost or by animating a mummy. Some wealthy people had the bodies of animals or commoners mummified and placed in their tombs to become undead guardians. Egyptians didn't perform human sacrifice to create tomb-guardians, although in a fantasy campaign some particularly ruthless magician might do exactly that.
Egyptian tombs also contained a variety of traps: pits, mechanisms that fired poisoned darts, blocks of stone positioned to fall either on or behind intruders, killing them or sealing them in, and so on. Tombs seldom contained enough space for elaborate mazes, but some contained twisting corridors that led to dead ends and decoy graves. Any of the traps which appear in fantasy dungeons might show up in an Egyptian tomb, although probably not in the usual profusion.
If magic exists, magical tomb defenses are common. Medieval Arabs believed that Egyptian sorcerers had turned the most valuable grave goods invisible, and that only those capable of speaking the appropriate passwords could ever find them. Because of their antiquity and the status of their owners, magic amulets stolen from royal bodies or magic spells copied from royal tombs were assumed by usurpers to be more powerful than those commonly available – the spells designed to protect the dead could actually attract robbers centuries later.
Of course, none of these defenses could protect the tombs from those who worked in the royal cemeteries – the priests of the mortuary temples and the workmen who dug and decorated the tombs. In Nubia is an example of a tomb robbed by way of an underground tunnel dug by a construction crew as they were building a tomb adjacent to it! Similar incidents occurred in Egypt proper, but only when workmen accidentally intruded on an old tomb while digging a new one.
The worst thefts in the Valley of the Kings were officially sanctioned under the guise of restoration and protection during the XXth and XXIst Dynasty reigns of High Priests Herihor, Piankh and Pinedjem, when dozens of royal mummies were removed from their tombs, unwrapped and "mined" for gold, and then rewrapped and hidden in a number of mass caches. The high priests also reused some of the "excess" grave goods in their own funerals – Pinedjem was buried in two recycled coffins of Thutmose I!