When a character reaches 0 hit points, that character is slain. The character is immediately dead and unable to do anything unless some specialized magical effect takes precedence.
Death From Poison
Poison complicates this situation, somewhat. A character who dies as a result of poisoning may still have active venom in his system.
Poisons remain effective for 2d6 hours after the death of the victim. If the character is raised during this time, some method must be found to neutralize the poison before the character is restored to life. If this is not done, then after the character rolls the resurrection survival check as given in “Raising the Dead” further down this page (and assuming the roll is successful), he must immediately roll a successful saving throw vs. poison or suffer all the effects of the poison in his body, as per the normal rules. This may only injure some characters, but it may kill other characters seconds after being raised!
Death From Massive Damage
In addition to dying when hit points reach 0, a character also runs the risk of dying abruptly when he suffers massive amounts of damage. A character who suffers 50 or more points of damage from a single attack must roll a successful saving throw vs. death, or he dies.
This applies only if the damage was done by a single attack. Multiple attacks totaling 50 points in a single round don't require a saving throw.
For example, a character would be required to make a check if a dragon breathed on him for 72 points of damage. He wouldn't have to do so if eight orcs hit him for a total of 53 points of damage in that round.
If the saving throw is successful, the character remains alive (unless of course the 50-hit-point loss reduced his hit points to 0 or below!). If the saving throw fails, the character immediately dies from the intense shock his body has taken. His hit points are reduced to 0.
The character may still be raised in the normal ways, however.
There are occasions when death is unavoidable, no matter how many hit points a character has.
A character could be locked in a room with no exits, with a 50-ton ceiling descending to crush him. He could be trapped in an escape-proof box filled completely with acid. These examples are extreme (and extremely grisly), but they could happen in a fantasy world.
Raising the Dead
Curative and healing spells have no effect on a dead character—he can only be returned to life with a raise dead or resurrection spell (or a device that accomplishes one of these effects). Each time a character is returned to life, the player must make a resurrection survival roll based on his current Constitution (see Table 3). If the die roll is successful (i.e., the player rolls equal to or less than his resurrection survival percentage), the character is restored to life in whatever condition is specified by the spell or device.
A character restored to life in this way has his Constitution permanently lowered by 1 point. This can affect hit points previously earned. Should the character's Constitution bonus go down, the character's hit point total is reduced by the appropriate number of hit points (the amount of hit point bonus lost is multiplied by the number of levels for which the character gained extra hit points from that bonus). When the character's Constitution drops to 0, that character can no longer be raised. He is permanently removed from play.