Fighting a Drider (lvl 4 group)

Hi there!

WARNING: Possible spoilers from Lost Mine of Phandelver.

I want to change the final boss of Lost Mine of Phandelver (a drow called Nezznar) and make him transform into a drider during the fight after losing Lloth's favour.

Would it be too much for a lvl 4 group of 4 players?

Thanks in advance.

They'd already be pretty beat up from the dungeon crawl, assuming they haven't long rested, so that would probably not go well for them.

Quote from Maruntoryx >>

They'd already be pretty beat up from the dungeon crawl, assuming they haven't long rested, so that would probably not go well for them.

 What if they had a long rest? Would it be a fair fight or will they be smashed by the drider?

Then they'd likely win, but it would be difficult. The Xanathar's encounter builder puts that at about Deadly difficulty. If there are creatures other than the Drider, the party is probably toast.

The real challenge of Wave Echo Cave however is that this is a large dungeon (don't forget that the grid in the cave is actually 10ft, not the usual 5ft). In addition, the wandering monsters make finding a place to long or short rest within the cave challenging at best. There are if I remember correctly just three rooms which can be secured well enough to take a rest uninterrupted within the cave. 

Assuming a 6 hour walk to Wave Echo Cave (15 miles), and the fewest number of encounters between the entrance to the boss (two) the party aren't going to have expended enough of the day to be able to take a long rest yet. Even if you assume the maximum number of non-random encounters (nine) between the entrance the boss the party are still very unlikely to have burned enough time to be able to take another long rest. Even disregarding combat encounters, Wave Echo Cave would take only around 10 hours to fully explore (assuming 30 minutes spent per 'room'). That's only just barely enough (6hrs travel + 10hrs exploring) to warrant a long rest. My point here? Wave Echo Cave is challenging enough if you don't go 'easy' on the characters and allow them to take long rests 'early'.

Back to the point though. Here's how a Drider final boss shakes out in my experience:

1. Party of 4 were all level 4, no feats, no multiclassing, short rest before encounter - 4 Giant Spiders, 1 Drider. Party fled the combat would have become a TPK otherwise. Fight lasted 3 rounds.
2. Party of 5 Level 4, with feats and multiclassing, short rest before encounter - 4 Giant Spiders, Nezznar, followed by Drider. No contest, one character fell unconscious for less than a full round, never a doubt that they'd win. Fight lasted 7 rounds.
3. Party of 4, Level 4, with feats and multiclassing, short rest before encounter - 2 Giant Spiders, 1 Drider. Druid fell unconscious in the final round, but the party were never in any real danger. Fight lasted 7 rounds.

I've run this more than just the three times, but these are from my DM notes on the adventure. The point here is that the options you choose to use or allow have a massive impact on the way this adventure plays out. Just the presence of a Druid for example can ensure that the party steamroll most of the encounters within Lost Mine. It is for this reason that in Phendelver and Below, the final fight becomes Nezznar and two bugbears. Nezznar's updated stat block makes him a bit more fearsome too. Discounting old Nezznar's spells, he had a +1 to hit with an average of 5 damage on a single staff attack. New Nezznar has two Poison Blast attacks per round with a +5 to hit, and average damage of 9. He's a lot more beefy. However, he needs to be to account for classes not in the basic rules, multiclassing, and the presence of feats.

My opinion honestly is to run Wave Echo Cave as written, if you're playing with pre gens. If not, run the Plandelver and Below version of Wave Echo Cave, it's built for all the options there. If playing 5.5e, then substitute the Phandelver and Below stat blocks for those found in the 2025 Monster Manual.