Adjusting Modules for More Players

Question

I am planning on running a D&D 3.5 campaign soon. I underestimated how many of my friends would be interested, and my group of 4 has quickly turned into a group of 6. I have seen various Encounter Level calculators and calculation tips, but I'm not sure that is what I'm looking for. I'm going to be running our sessions from modules rather than completely making each encounter from scratch, so I need more info on how to adjust what is already there then how to calculate the EL. I don't have all that much experience with DMing (I have done it some), and I plan to use a module such as "The Sunless Citadel" or "The Forge of Fury" (I know those are for different levels but I was just giving examples). The problem I'm having is that those modules have already calculated out an EL for you, but its for a group of 4 players.

How do I keep the encounter level the same for a larger group? Breaking down the precalculated EL the module gives me for 4 players into the CR's of the monsters and traps and then recalculating them and trying to add CR's so that the EL for the larger group is the same seems like a hassle. And with my lack of experience, I'm also worried I will do it wrong. Also, how do I deal with the premade "boss" monsters to make sure they aren't underpowered for the larger group?

Answer 1

Quickly, I thought that my DM wrote this question, because we were in that exact same scenario. What helped us was:

1. The experienced players knew the material, and each took a pupil to help guide the new players. We're still having trouble actually "roleplaying" as a group. Most still treat it as a series of battles and not as an interactive story. We're getting better as a group, but be prepared for inexperienced players to decide that all they want to do is kill things. An overwhelming battle is a good idea for this. Make them need to retreat/consider not engaging.

2. Our DM used the total number of players as the guideline for us. Instead of 6 orcs, there were four orcs and two ogres. Instead of a group of skeletons, there were two wights and a high level mummy. Some caused problems, some didn't, but it was all fun.

3. Never underestimate the power of deus ex machina. An inexperienced DM can overwhelm his party. He can also use deus ex machina to solve the problem he created. For instance, we are a group of 6 (2 experienced players), and we had an encounter suitable for 8 characters. When it was clear we were in trouble (it was our 3rd/4th encounter), the DM used his god-like powers to help us out. We were near a town, and townspeople "witnessed our heroics and were inspired to help us" and took some flanking positions near some of the weaker enemies. This allowed our healer to retreat and heal the two tanks, and the rogue and ninja to clear out using sneak attacks. I think one villagers did 2 damage with a pitchfork. The damage wasn't the important part, but the attacks weren't centered on as many of the party, and the flanking helped with extra damage/increased attack rolls.

Just remember to think of creative solutions to problems that you will create, even just by mistake. In a dungeon, perhaps a trap springs and hits an enemy, rendering him unconscious for 5 rounds. Thing like this will allow the newbies to learn combat, and you can phase out the deus ex as you learn to better estimate your players skills and knowledge of the game.

Answer 2

First an aside before I address the core of your question: Follow your gut instinct and severely restrict what your players can choose for characters. I'd strongly suggest PHB-only for two reasons: your inexperienced players will be able to absorb that much information eventually, and your experienced players can't break it badly at all. You don't want to overwhelm your new players and you don't want your experienced players either leaving them in the dust or end up effectively taking over other players' character-development choices in the name of "optimisation".

For your core question, I'm going to suggest a radical proposition: don't change anything. (Yet.)

Why? Again, two reasons. First, because anticipating the exact difficulty ahead of time is actually really hard. The CR system is already an approximation, but it's far from perfect. In fact, the degree of error that the CR system inherently has is going to be larger than the disparity introduced by increasing the party size by two. So given that it's an imperfect system, and given you're a new DM, you're unlikely to actually fix anything ahead of time. Which leads into reason two to leave it alone…

As you play, you'll accumulate DMing experience and direct evidence for what sort of things make encounters easy and hard for your group. The CR system is an idealised abstraction that can't possibly account for the particular strengths and weaknesses of your player group and their characters. As you gain more confidence as a DM, you'll learn how to tweak encounters to make them challenging and fun. Once you've got that experience, you can tweak encounters way more effectively than you can now.

And, as a bonus reason to not worry about it: The CR system was never meant to be a way to perfectly-balance your game. It was actually intended to be merely a way of estimating the difficulty of an encounter in general without the expectation that fights would be "even" with the PC party. You are entirely correct and safe to send your players' PCs up against easy fights, and up against hard fights. If you tailor your encounters too closely to the "level appropriate" CR then you encourage your players to turn off their brains and not consider whether a fight is a good idea or whether they need to get creative – and a creative mental game is certainly not supposed to turn off the players' brains, right?

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So, to sum up this answer: Your best system for adjusting CRs is your own experience, and you need to give yourself time DMing the game to get that. In the meantime, you absolutely will not break the game or run a sucky game by having theoretically-underpowered encounters. Your players will still have fun, even if there are only 8 orcs in that room instead of 11.5 orcs.

Answer 3

For most encounters it's as simple as adding a few more monsters. In this case, 50% more. The target ACs and save will still be in their range, but there will be more of them. Likewise, every other trap is now has a second trap. The EL's stay the same because both parties have the extra resources, it should be just as hard if they had 4 players... As long as you ignore choke points, area affects, and scaling issues.

End bosses are different. There's just the one of him. You'll have to increase his AC, raise his damage output, give him more hitpoints, and/or give him some minions to order around. Honestly, just eyeball it. Don't be too hung up on nailng the EL exactly. Most of the threat of an encounter depends on how smart you play the characters anyway.

MAJOR WARNING
Prepare for soul-grindingly slow progress. D&D past 5 players takes FOREVER. And adding extra monsters doesn't help any. If you can't get out of having this many players, insist on some rules to keep it moving. Announce who is on deck, and expect them to have their action decided when you point at them. You could even have them roll it ahead of time. Demand they know their spell effects, or it fizzles. Answer their questions, but insist they decide what to do within 6 seconds. They'll have minutes to think while other people are acting. Accelerate/guesstimate interactions between NPCs.

Answer 4

In general, increasing the number of the same type of monsters is a much safer solution that increasing the CR of monsters. There are a couple of reasons for this. First, when you increase CR you generally increase HD, which means that you're running up against higher to-hit, saves, and saving throws. I recommend Trailblazer's systemic analysis here, but basically the gist of it is that CRs of party level +3-4 or higher are really, really dangerous without proper preparation, and +6 is likely a PC kill even with decent prep. On the flip side, if you use fewer, higher-power monsters, you also introduce an action-economic advantage for the PCs; for example, with 6 PCs against 4 (more powerful) monsters, they're getting 1.5 actions per monster action, whereas 6 PCs versus 6 normal monsters is 1 PC action per monster action, and balances out with the module author's expectations. Using one big monster tends to produce very swingy combats; if it wins initiative, it'll squash a PC in the opening round, but all it takes is one failed save and it's toast. Using more monsters means a gradual degradation of fighting capability.

So, my recommendation for most encounters (those with a handful of weak monsters) is just to multiply the number of monsters by (partysize) / 4. Bosses are tricky, but one tactic I've seen used successfully is multiplying boss HP based on party size and granting it extra actions (for example, the ability to act twice per round, once on its initiative and once on its initiative minus 10). Balancing extra actions is tricky for non-multiples of four-sized parties (though you could grant it an innate haste-type effect as an x1.5 approximation), but it takes a good bit less paperwork than adding minions, which is the other best option. What you generally don't want to do is provide blanket bonuses to saves, AC, and SR, as these can rapidly make the monster untouchable. Increasing HP is usually a reliable policy; if they could kill it before, they can still kill it now (barring things that require special types expendable of damage like incorporeal undead with force effects or trolls with fire).

Also, from personal experience running Sunless Citadel for a 6-man party, you may want to enlarge the rooms and corridors, possibly by a factor of 1.5 in all dimensions. We ran into some serious cramping issues.