Why not reset the monsters to the level of the players?
because the party's strength is now below the lowest level for that monster type.
If your party can drop power at any point in the game then you can allow the player grind or do other things to boost your party strength.
yes. of course this is always an option. come back with a few more friends...or skills, or weapons, or all of the above. that kind of idea. everything necessary to do that is already in the game.
I think there is a sense of accomplishment to planning out on how to defeat said monster, executing the plan and succeeding.
yes, completing the quest at that point becomes quite a bit more challenging, and thus more rewarding. OTOH, the need to gather numerous followers may be discouraging for those players who simply seek action. but there's always cavern (IE dungeon) exploration for folks just looking for action. quests are more appropriate for players looking for a more mission driven gaming experience - sometimes its nice not to have to decide what to do next. by contrast, caverns offer free-form exploration with lots of action in a small area.
If you're in a group that's been weakened and you know that there's a tough foe over the next hill, why would you go over the hill?
you know how players are! <g> adjusting number appearing to party strength will keep things balanced until the party is weaker than just one appearing of the monster type. after that, they're screwed. but then again, they probably ought to be - as you point out.
Or is the problem that the player has no way to tell that he's out classed?
when the player returns, the number appearing is based on the strength of the now weaker party. but you can't have less than one appearing. if party strength is less than one appearing, the player may not realize they are still outclassed until they give it a go (and most likely die).
I've been warned about the deathclaws ahead, I know what they can do, so while I might've been able to deal with them with that awesome weapon I had awhile ago, I am not running through the short cut without it.
i run through the shortcut all the time! <g>. my personal best is making it across while just 2nd level. but i cheat and use the navmesh to my advantage. <g>.
If you can tell that a particular encounter is going to be too difficult, could you have that encounter maybe just move to somewhere that makes sense leaving the player an opportunity to be stealthy and survive?
you don't really know until they re-trigger the encounter. at that point you can check party strength and spawn appropriate numbers of the monster type previously discovered there. but you can't spawn a third of a baseline dragon - so to speak. and moving the dragons elsewhere doesn't really change anything.
It almost sounds as if you pin the party into that "quest encounter" and they can do nothing else till it is complete.
all quests are optional and can be abandoned at any time for any reason.
the only thing that's pinned down is what kind of monster they ran into the first time, and thus what kind of monster they run into when they return.
the problem can occur when the party is strong enough for that monster type the first time, but not strong enough for even one of that monster type when they return.
....This would allow weaker areas to exist for building up new party members or weaker ones.
number appearing for random wilderness encounters is always adjusted to party strength. so all areas are always the appropriate difficulty for the party. not all wilderness encounters are supposed to be winnable. survive-able - maybe. winnable - no. so a 1st level player encountering one 28th level stegomastodon (the biggest critter in the game) in the wilderness is not an issue. quests on the other hand should be challenging but winnable.
Think allowing the monster to have dynamic level scaling is the best option.
yes, but a level 1 dragon is just silly. say a party has the strength of 10 men based on numbers, experience , skills, and equipment. and lets say dragons start at level 10 minimum. the party encounters the dragon but leaves for some reason. time passes, they do other things, some members leave the party or perhaps die. eventually the player returns, lets say alone, and is the equivalent of 3 men. well, a baby dragon is still the strength of at least 10 men, so the player probably dies. and weakening the dragon further would probably be too unrealistic. this is supposed to be a dragon after all.