Question
I am currently running Lost Mine of Phandelver for a group of new players. There are a total of six characters, but they are getting Exp "as if" they were four (I'm balancing the encounters for that, as well, although the math doesn't match exactly). I'm used to adding "rival" parties in my homebrew campaign (the rival party is of NPCs, to be clear), making "side quests" a limited resource. In homebrew, it's easy to balance that, as you make enough side quests for the players to be able to proceed the main quest after the resources are removed. For published adventures, that's a little harder.
Chapter 4 from LMoP states
This part of the adventure is designed for characters of at least 4th level and assumes that each character has earned at least 2700 XP. If the characters skipped too many of the optional investigations and encounters in part 3, they might not be 4th level, and many encounters in this section might be difficult for them.
This implies that it's fine to skip some side quests, while certainly not fine to skip all of them.
The question:
- How many side quests can I take away from the party (and give to the
"rival party") without hurting them too much? - What particular side quest I should be worried about?
My main concerns are obviously XP and Magic items. Gold, generally, should not be a problem. Taking away every way of finding the Castle is obviously bad as well.
In general, I think this question can easily be answered by expertise since many groups probably did not run all the side quests and were able to finish it quite fine.
While this is a Q&A, I'm interested in expertise from players and DMs who have run the adventure and only partially finished the side quests. A particular concern is for relevant magic items that shouldn't be lost to the party.
Party Context
The party has a Life Cleric and a Paladin, so Potions of Healing are not being a problem until now. Other than that, there is a Barbarian, a Warlock, a Ranger and a Druid.
The party has rolled for stats, and honestly, most of them got considerably better than average. In particular, the Barbarian has absurdly strong stats (19 Str, yes, at level 1, 16 Con and 14 Dex).
Please, don't answer with "don't put a rival party, that's a bad idea" or anything along these lines. That's something I enjoy doing, players usually enjoy having this challenge, and I have already talked to them and got their acceptance on that.
If you suggest including extra side quests, especially if you want to suggest a particular side quest, please only do that if you have played that side quest.
As a note, I'm worried about taking away side quests. If the players decide to not do them, that's their problem. (Before someone tells me I'm railroading them or something).
Best Answer
Disclaimer: Possible spoilers about LMoP.
So, I have read through the rewards of the third chapter, plus the "starting point" of the two first chapters. The needed encounters to reach the recommended 4th level can be answered by math. From a point of view of experience, for 4 players, you need a total of \$ 4 \cdot 2700 = 10800 \$ XP for the party.
The first chapter gives you a total of \$1400\$ XP (350/character).
The second chapter gives you a total of \$+2800\$ XP (+700/character).
The Cragmaw castle, from the third chapter, gives you a total of \$+4400\$ XP, assuming
From the main story, we have a total of \$ 8600\$ XP. That means the Side Quests should give the party at least \$10800 - 8600 = 2200\$ XP. I have split the side quests in four: Agatha (sent by Sister Graele), Wyvern Tor (sent by the Mayor), Old Owl Well (sent by Daran) and Thundertree (sent by Quelline Alderleaf).
\begin{array} {|r|r|} \hline \textbf{Side Quest} & \textbf{Total Awarded XP} \\ \hline \textrm{Agatha} &200 \\ \hline \textrm{Wyvern Tor} & 1250 \\ \hline \textrm{Old Owl Well} & 1000 \\ \hline \textrm{Thundertree} & 3750 \\ \hline ~~\textrm{Westernmost Cottage} & 50\\ ~~\textrm{Blighted Cottage} & 50\\ ~~\textrm{Brown Horse} & 200 \\ ~~\textrm{Blighted Farmhouse} & 200 \\ ~~\textrm{Ruined Store} & 400 \\ ~~\textrm{Dragon's Tower} & 2000\\ ~~\textrm{Old Smith} & 100 \\ ~~\textrm{Herbalist's Shop} & 200 \\ ~~\textrm{Old Garrison} & 250 \\ ~~\textrm{Weaver's Cottage} & 150 \\ ~~\textrm{Dragon's Cultists} & 150 \\ \hline \end{array}
Essentially, the side quest giving the most XP is, by far, the Thundertree, due to the Dragon encounter. It is also the encounter that gives the most valuable magic items - +1 Weapon, 2 scrolls and 2 potions. Old Owl Well also gives a Ring of Protection, which is important.
From that, simply don't take Thundertree from the party, which is also the safest way to learn about the Castle's Location through Reidoth. That doesn't even account for the random encounters.
As a second option, the Cragmaw Castle can be skipped, actually, as long as the party can get \$400\$ XP from the random encounters, which shouldn't be hard.
As a side note, you shouldn't be worried about the PCs being able to find the Castle. The Goblins and Hobgoblins from random encounters are able to provide that info, so the party only needs to wander around for some time.