Do spell effects end early if the target or caster dies?

[Echoen]

If a spell effect on a creature is active, and that creature dies, does the spell effect cease/end/dissipate?

[Castilliano]

It would depend on the spell.
There's no default link between the caster and their own spells after casting, but many spells do depend on the caster and/or target being alive to continue. If you set somebody on fire, their body would remain on fire (though note that'd be brutal to burn key equipment so it's more flavor than mechanic). If the target dies, they do become an object, and that will end many spells which require a living subject, i.e. Charm. I suppose that's one way to break many effects. :-P

[Guntermench]

They'd last their duration, unless they're Sustained in which case they'd end when the dead guy misses sustaining them.

[breithauptclan]

I would agree with the above for a strict reading of the rules (though I would mention that gaining the Dying condition does not mean that the character is dead and wouldn't end spells that require a living target).

However, many times it will be run differently in actual gameplay because it would be annoying or irritating to do it by the book.

We recently had a battle with an enemy that cast Confusion on one of our PCs a round before dying and ending the combat. We didn't play out the 10 rounds of 'combat' of the rest of us trying to deal with the confused character attacking the party. That wouldn't have been fun. Instead the GM simply had the spell effect end once the caster character died and the encounter ended.