PCs die when...

[Slobber Monster]

They reach -10 hit points without stabalizing. Sometimes it's a dramatic moment, sometimes it'll be when a kobold gets one last lucky shot with a spear. When it comes to combat, you just never know.

I'll go with this, plus add the observation that by far it most often coincides with some sort of player stupidity.

 

[Masquerade]

. . . it's most dramatic.

 

[JRRNeiklot]

"When I dm, player characters die."

 

[Olgar Shiverstone]

- they choose not to retreat
- they let the bad guys reinforce
- they wander cities of undead without a cleric
- there is spellcaster friendly fire
- they split the party
- I roll my white d20s

 

[xnosipjpqmhd]

...its getting late in the campaign.

ironregime

 

[Bloodstone Press]

pcs die when the dice say they do.

 

[Aust Diamondew]

the Fates decrees they must.

 

[Edgewood]

They try to attack a god while still at 9th level. Actually I didn't play out the combat. i just tore up their character sheets, and asked that they have new 1st level characters ready for the next session, then went home....

 

[The_Gneech]

They decide to go for "just ONE more room."

-The Gneech

 

[Eloi]

..they tick off Kotik2.

Then they die. In fire. Simultaneously. Before they comprehend how badly they erred.

Ask her yourself, she'll tell you the same.