View source for Tome of Necromancy (3.5e Sourcebook)/New Rules

=== Tombs ===

While most tombs are merely places of rest for remains, some tombs become focal points for Negative Energy as hundred of years pass in the presence of the dead. Also, years of habitation by undead creatures in an enclosed space can also wear at the boundaries of the Negative Energy Plane. Some Necromancy effects can create or exploit this property. The game effect of a Tomb is that all undead inside it gain fast healing 1 and cannot be Turned or Rebuked, and spells with the [Tomb] subtype can be cast within it. Undead cannot be created within the confines of a Tomb, and creatures slain by undead do not become spawn.

Tombs are always enclosed places, and if they should ever be exposed to sunlight (by smashing in the roof, for example), they lose all special properties and no longer confer effects to undead creatures.
Level Adjustment	0 +
Skill	Appraise +, Balance +, Bluff +, Climb +, Concentration +, Craft +, Decipher Script +, Diplomacy +, Disguise +, Escape Artist +, Gather Information +, Hide +, Intimidate +, Jump +, Knowledge +, Listen +, Move Silently +, Perform +, Profession +, Sense Motive +, Sleight of Hand +, Speak Language +, Spellcraft +, Swim +, Disable Device +, Forgery +, Open Lock +, Search +, Spot +, Tumble +, Use Magic Device +, Use Rope +, Handle Animal + and Ride +
Skill Points	4 + and 6 +
Summary	A revenant is the victim of a murder driven to avenge their own death. +, A vampire is an unliving mockery of life that lives by cruelly consuming the blood of the innocent. +, Characters with at least 2 class levels brought to zero Constitution by Ghoul Fever find their constitution restored and begin their unlife as Ghouls + and A character slain in battle may return as a Sword Wraith if his services were hired under false pretenses or if his exploits were particularly impressive before his life finally ended (at the discretion of the DM). +