"False doors", also known as "Ka doors" as they allowed the Ka (an element of the "soul") to pass through them, were common in mortuary temples and tombs from around the Third Dynasty and temples of the New Kingdom. The false door was thought to be a threshold between the world of mortals and the world of deities and spirits. The deity or the deceased could interact with the world of the living either by passing through the door or receiving offerings though it. As a result it was not uncommon to find false doors depicted on the sides of coffins as well as on the cabinets of "shawabti" ( or "ushabti" - magical servants).
During the New Kingdom false doors in temples were often associated with a chapel known as "the hearing ear" which was generally located in the outer wall near the back of the temple close to the sanctuary. These chapels allowed those outside the temple to communicate directly with the god who could hear them through the false door. However, the majority of false doors are to be found in tombs and mortuary temples to allow the deceased to access the living world and receive offerings. In fact, the false door can be seen as the combination of an offering niche and a stele with the offering formula inscribed on it.
Many false doors were modelled on the "palace facade" design found on the outside of Early Dynasty Mastabas and on the outer wall of Djoser´s step pyramid. A Typical false door has a long, narrow recessed panel which represented the actual doorway. Above this, a semi-cylindrical moulding represented the reed mat generally used to close a real door. The narrow panel and moulding are set inside a rectangular frame, often topped by a by a rectangular panel decorated with an image the deceased sitting in front of an offering table. The offering table took the form of the "hotep" hieroglyph (a breadloaf on a reed mat representing an offering) and the offering formula was genetrally inscribed around him or her. Outside this is was common for there to be an architrave (a rectangular frame). The False door was usually placed on a lintel (false or real) that extended across the door jambs and generally included up to three pairs of jambs leading to a central niche.
There was often an offering table in front of the false door on which offerings of food and drink were placed. The offering tables were usually made of stone and were often decorated with depictions of typical offerings (bread, beer, fowl, ox) and with depressions to receive offerings.
From the middle of the Fifth Dynasty the
decorations often included torus moulding (convex moulding resembling a
semicircle in cross section) and a "cavetto cornice" (a concave bracket around
the top of a wall or gate with a cross section that resembles a quarter circle
in cross section). It is thought that these decorations represented the plants
originally used to build predynastic buildings. Images of the deceased were also
fairly common. Usually the decoration was undertaken in such a manner that the
deceased appeared to emerge from the false door itself.
Along with the name and titles of the deceased, and the offering formula, the decoration on the false door often included a curse to those who would harm the deceased and a blessing to those who made offerings. For example, the false door in the tomb of Redi-ness at Giza (G 5032) has the following text inscribed on it.