Death saves are fine and one of the cooler legacy things kept from 4e.
Deadlier? Like an earlier suggestion, some NPCs would play for keeps with coup de gras, etc. . Particularly at higher level or if Mr. Cleric is around or if the PCs have nasty habits like coming back from the dead.
Handling it for NPCs? Don't have the books with me, but either the PHB or DMG says it is a DM option to use it for the Big Baddies. I personally would not use it for mooks. Too much stuff to keep up with as it is with some of the more complex combats we as DMs run.
Deadlier? Like an earlier suggestion, some NPCs would play for keeps with coup de gras, etc. . Particularly at higher level or if Mr. Cleric is around or if the PCs have nasty habits like coming back from the dead.
Handling it for NPCs? Don't have the books with me, but either the PHB or DMG says it is a DM option to use it for the Big Baddies. I personally would not use it for mooks. Too much stuff to keep up with as it is with some of the more complex combats we as DMs run.