Death
Death is the game result that occurs when a levelled character's hit points are reduced through damage to less than a total of minus 9. In the case of non-levelled humanoids, death occurs at minus 4 hit points or less. With all other creatures, counting the majority of monsters and animals, death occurs at zero hit points.
When dead, the character or creature ceases to function and are no longer able to take any actions or participate in the game. Under normal circumstances, the player begins the process of creating a new character, who then joins the ongoing campaign.
Causes of Death
In addition to the metric of loss hit points, death comes from a variety of factors, namely combat, disease, dehydration, falling, wounds, old age or uncompromising effects resulting from the natural environment — after all, a character may die after being swept overboard, or during a volcanic blast, or as a result of earthquake or flood, or due to the collapse of a mine or the lack of breathable air.
Every so often, characters meet their untimely end without any fault of their own. Despite taking every conceivable precaution and steering clear of undue risks, an unforeseen roll of the dice seals their fate. These moments, although distressing, are an inherent aspect of the game. Indeed, the ever-present possibility of death is pivotal in upholding the tension and momentum of the game. Just as players may claim unexpected victories through a fortuitous roll, synchronicity dictates that these twists of fate may also befall the players themselves.
Limits upon the Dungeon Master
In cases of character death, the DM is subject to the rules just as the players. However demoralizing it may be for the party to lose a cherished character, even in circumstances that render them irretrievable, for the game's sake, the participants must accept the outcome — or else the game's rules and consequences have no meaning. Ultimately, death encourages resilience and fortitude within the player, encouraging them to become better players and better people. The specter of death intensifies the sweetness of victory, as players grasp that death is an actual and ever-present possibility, fostering the strength to confront and manage difficult situations both in the game and in real life.
Restoring Life
Rules do exist to restore a dead player to life, under circumstances that are individually described in the rules associated with the spells death’s door, raise dead, resurrection, reincarnation, alter reality and wishing. Each has its difficulties and drawbacks, which are also incorporated in the game's rules, assuring that is neither easy nor certain that a dead character can be restored to life.
See also,
Animate Dead (spell)
Character Creation
Constitution (ability stat)
Damage (hit points)
The Adventure
Undead