What do I think these presumptions are?
- Combat is neither the universal nor always even a viable option to get past every challenge. Straight combat should not always be a good idea. The notion of, say, a basilisk creates important tension, i.e. "The ancient treasure is guarded by a feasome beast, whose very touch, or even the sight of whose eyes, will turn you to stone! Not even the mightiest warrior, however healthy he be, is safe from the monster's gaze. But, it is said that those who turn their eyes aside might stand a chance, and should you trick it into looking at its own gaze with a mirror, it will turn itself to stone." The players may still opt to risk the combat, or they might try other tactics to bypass the monster.
- Character (and monster) saves improve absolutely, and not only relatively, at higher levels. That is, generally speaking, the poison of an 8 HD monster is no more virulent than that of a 1+1 HD monster. Saving against an 8th-level spell cast by a 16th-level Magic User is no more difficult than saving against a 1st-level spell cast by a 1st-level Magic User. While saves are never a sure thing, this means that higher-level characters are simply less threatened by threats that require a save or take them out, whether temporarily or permanently (i.e. death, turn to stone, paralysis, polymorph, etc.). This is crucial, I think, because it means that a high-level character can take more reasonable risks in facing foes with save or dramatic effect abilities. Likewise, it means that Magic Users, however powerful, are still less likely to take out powerful foes with just one spell. They might do so, but it's a resource management risk (e.g. do I use the Dispel Evil to try to disintegrate the vampire, with no effect if he saves, as is not unlikely, or do I save it to, say, remove a curse?).
- Players are at the heart of the game, not characters. Here's what may be a more dividing point. The presence of save or dramatic effect abilities, while hardly resulting in a pile of corpses of PCs, will likely lead to a higher incidence of character death than not having them. Even effects like paralysis can be life-threatening to a character, since the remaining party might need to retreat (and thus leave the unfortunate character to be a tasty snack for ghouls, carrion crawlers, or gelatinous cubes). If it is relatively easy to roll up a new character and the set up is not so complicated that it is relatively easy to drop the new PC into the game (say, almost as soon as the new character is rolled up), then this need not be a problem, if the player and not any specific character of his, is at the heart of things.
- Classic real and fantasy effects mean more or less in the game what they mean in the inspirational sources. Poison from asps is deadly, and in quite a short span of time. The gaze of Medusa could turn even the mightiest hero or monster to stone. Witches can transform princes into toads and adulterous queens their husbands into wolves without first having their henchmen beat them up to get their hit points low enough for the spell to work. Save or dramatic effect abilities reflect this.
- At least some foes with save or dramatic effect abilities have either an Achilles' heel or compensating weakness. Undead can be turned and are vulnerable to holy water, and some undead have other weaknesses (e.g. a vampire's aversion to garlic and the cross/holy symbol of Law or Good). Several monsters with gaze powers can have their effect avoided by averting one's gaze and at least some of them are vulnerable to their own gaze being reflected back. Some have a limited use of their ability (e.g. the banshee's groan). Magic Users (who have a larger array of save or dramatic effect spells than other classes) are limited in hit points and armor class, so they are fragile, and can, in addition, be rendered ineffective if silenced, gagged, etc.
- Save or dramatic effect magic presumes a limited array of spells and that these cannot be used repeatedly. In other words, either Vancian magic, or at least all save or dramatic effect spells must be dailies (and for monsters, some might be limited use per day or, if using 4e concepts, only after they "recharge").
There may be others, but this is a start.
I do think that save or dramatic effect abilities are a good idea, but that is in part because I share the logic of the presumptions listed above. Nonetheless, I also think that weaker foes should have relatively weaker effects (not so much death as short-term paralysis or somewhat incapacitating disease, e.g.), which was not always the case (as almost every poison up through 2nd edition caused death on a failed save, and poisonous creatures were hardly uncommon at 1st level).
Are there any other presumptions that would need to be in the game style/rules/presentation to make save or dramatic effect abilities and threats a fun, rather than odious, part of the game?