It seems that quests of the same level vary difficult *a lot*, even if they are both "of average difficulty" according to compendium. You never know if you can beat a quest, I guess that only comes with experience
For example:
I did tangleroot elite (last part lvl 9!) with a lvl 4-7 party *easily* with a lvl 4 rogue getting the traps with no problem
Then I tried (emphasis on "tried") House K quests , they are about lvl 7-8 on elite with a lvl 7-9 party and we got murderered, rogue lvl 8 couldn't find the traps, and traps doing 100+ damage, difficult mobs, fire elemental unbeatable; xp bad as well
From what I've noticed so far, (I'm only lvl 8) is that chain quests (they are all p2p but waterworks) are easier and more xp, than most single quests
And some quests are absolutely not worth it to do at lvl, especially not hard/elite...better run through later overlevelled , just for favor
Btw this is not a whine, I'm up for a challenge! But taking 1hour for a short quest, dying 6 times and having to replace several people and in the end still failing the quest, getting no xp and favor is not my idea of fun...
seems ok for a raid but not a lvl up quest
I have no clue how f2p players can bear lvl 6+ on just the marketplace and house quests
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Quest difficulty
KORTHOS & HARBOR: all quests doable at lvl... hardest quests irestone (especially elite) and where there is smoke there is fire (esp elite)
WW: not hard
MARKETPLACE: only few quests worth it, most doable at lvl , except swiped signet, gladewatch and freshen the air
CATACOMBS: easy
STK: easy on normal and hard; traps in part 3 are mean on elite
DELERAS: easy on normal, havent done hard and elite yet
TANGLEROOT: easy
HOUSE K: the small quests from the inn: need excellent rogue, lots of resists and better be higher lvl than the quest
someone else continue if they wish :-)