Stat Death

A rule where death occurs as a result of a primary stat being reduced to 0. Your extremely out-of-shape Wizard tried out an unidentified -5 ring of strength? His bones and organs are crushed under his own weight. Your profoundly stupid fighter got his Intelligence sapped by a Mind Flayer? He forgets how to breathe. And woe to the hero whose Dexterity falls to 0, who suddenly slips on a banana peel and breaks his neck.

Stat death is used in RPGs to counteract extreme Min-Maxing. Players who fail to invest in their Dump Stat face extreme risk of embarrassing and anti-climactic death.

Board Games

 * In Betrayal at House on the Hill, if any of a character's four stats are reduced to the skull at the bottom of its counter and the haunt is in effect, that character dies.

Card Games

 * Variants in Magic: The Gathering:
 * If a creature has 0 Toughness then it dies. No, you can't regenerate it; no, being Indestructible won't save it. Creatures simply can't exist if they don't have positive toughness. The same clearly doesn't apply to Power.
 * A player loses the game if they need to draw a card and there are none left in their Library. As the Library represents the player's mind, with many cards that disturb it implying cracks in sanity, this can be thought of as the player finally succumbing to madness from intelligence draining.

Tabletop RPGs

 * In older editions of Dungeons & Dragons, zero constitution is fatal. Zero in another physical stat means you're physically helpless and immobile, but you can still use some mental or magic powers. Zero in any mental stat means you're comatose and drooling. (In 4th edition, stat damage is no longer possible.)
 * In GURPS you die if aging causes any stat to drop to zero. If some other force drops a stat to zero you're rendered all but helpless.
 * In Mutants and Masterminds, Constitution drain won't kill you outright unless you would have been drained below zero, but landing at 0 will still put you in a very bad way.
 * This is the way damage works in Traveller, where the only damage is to your physical statistics - if two of your physical stats hit zero, you're helpless; when the third joins them, you die.
 * In most games in the New World of Darkness having your Stamina brought to zero causes you to swiftly weaken and die of illness in days. Similarly, if your Karma Meter (Humanity for vampires/Prometheans, Morality for mortals, etc.) hits zero, the character becomes a monster, either literally (vampires) or figuratively (most everything else). They may not die, but they become unplayable.

Video Games

 * Dungeon Crawl which, as shown above, has specific cases in the source code for KILLED_BY_STUPIDITY, KILLED_BY_WEAKNESS and KILLED_BY_CLUMSINESS.
 * Nethack: if your intelligence drops to zero you die of "brainlessness", and not even an Amulet of Life Saving will save you, you are Deader Than Dead. This mostly happens because of Mind Flayers, which drain your intelligence by eating your brains.